Thanks for joining me on the live chat guys, I have just refreshed my page and you have all disappeared so apologies for not signing out!! I am still getting use to tech and all this UA-cam stuff!! I had better stick to carpentry!!
Hi Robin Thanks for your reply, could I just add. For the client any building work comes as quite an intrusive shock to most of them and having a lot of builders thrashing around can be very distressing for them, as they don't always envisage what is going to be involved, for some rather than being an exciting time it can be very upsetting. I never let any one on my jobs rush around or go any where they are not supposed to be an to show respect to the client at all times. I think that these screws lessen the impact for the client and make it a more enjoyable experience and that has to be good and they keep the the mess down for a better environment to work in. Great work as always Robin, tough times at the moment.
Hi Robin. I work at a builders merchants in the North West. Another company that installs groundscrews came in and spoke to me about them. It was the first id heard about these and I was blown away. Great idea instead of concrete.
Hi Robin, What I like about this form of construction it is a lot less invasive and you haven't got all that spoil from foundations. Makes for a nice neat job as always.
Excellent video, thanks Robin. We had a garden office pod built last year. Roughly 5m x 4m footprint, used 12 ground screws. Setting-out and installation took about 4 hours start to finish so construction of the structure could start next day. Very impressive form of foundation. We are in discussions with our architect about a rear extension to our house (approx dims 7m x 4m) and have asked her to speak to the engineer to see if we can use ground screws for that too. Saves a lot of time, money, disruption and CO2!
Just crossed my mind as we that these could be used as part of the electrical installation. The screws could be used as a multi rod TT earthing system.
I remember something similar on a DIY SOS many years ago. They used impact to screw them in, but had to wait for a flint wall they were building to harden because the vibrations were causing it to settle.
Hi Robin, I’ve just built a cabin in my daughters garden i used 28no 750mm screws all put in by hand, very good idea but hard work by hand that drill set up makes it look like a doddle thanks for the vid 👍
A small suggestion is that you can connect the grounding cable of your house from these nails and secondly, all nails should have a communication cable between each other And add an anode to prevent all this from being affected by static electricity
Hi Robin cracking video, the screws are a cool idea quick and easy foundation and very cost effective I would assume look forward to the next phase, quick question who signs them off engineer or the screw company all the best Tony 👍 have awesome weekend
Hi Tony, these get signed of by building control based on the pull tests and our overall loadings etc, have a great weekend to mate, all the best Robin
The caveats near the end are important. In my project I had heavy clay and it wasn't possible to drive some of the screws very deep even with that massive torque arm, so some of the screws were swapped to shorter versions. Plus we hit rocks. When you hit a rock you're a bit screwed (no pun intended), because you've already disturbed the ground, and you really want that position, so what do you do? The end result was screws not perfectly located and/or not perfectly plumb, which was time consuming to correct for (I fabricated some ugly but strong epoxy mortar shims). Now the level of professionalism of the installers wasn't as high as is evident here, but the lesson is: design so that you can cope with slight variations in position. I think if I ever do another similar project I'll just pour concrete piles. I think these screws work best when you have deep but workable subsoil.
Heavy clay isn't too much of an issue, it can be overcome by either pilot drilling with an earth auger or by taking a measurement to see how high that groundscrew is sitting. That screw then gets removed and cut shorter - if you haven't got a shorter screw that can be used. As the ground has been disturbed, the hole gets filled with 10mm gravel and the groundscrew driven back in. The gravel acts like a rawlplug, it gets compacted into the ground around the screw giving it good purchase. A pull test will confirm that its well in.
Yes, the "ruined" soil can be fixed with a smal stone mix. Take the pole out and pour the small rocks on the hole, then put the screw back and redrill! Quarantine solidity as original 😊
Hi Robin, Great video, I’ve just looked into using these here in Australia for a deck I’m going to be building. The are quite cost competitive when compared to digging or using a post hole digger, disposing of the soil, concrete delivery and concrete pump, and all the labour associated with this. Ground Screws can be done easily in 1 day, and saves a heap on my 50 year old back.
Thanks for sharing. With the weight of building structure sitting on ground screws, wouldn’t of thought you need to be concerned about pulling screws out, more if the sink in the ground under the loading. Back to front test I think.
What about a ground survey to both determine the suitability of the ground and to ensure you don't screw into 'anything important' like drains, pipes, cables, etc?
What's the point of the pullout test. The screws are not subjected to a tensile force. You would need to undertake a static axial load test. Add some kenteldge and see if the screw settles
Nice Robin saves all that concrete, not too mention the digging would of been nice of you to introduce the guys doing the screwing, keep up the great videos 👍
A pull test can be used to measure the compressive capacity as well. Typically a tension test will give a lower value, but the load in either direction is primarily a function of the engagement/contact area of the threads and the strength of the soil. The reason a pull test comes out a bit lower is you may get some extra capacity from the end bearing of shaft when pushed down. That said, their test was meaningless. They should have used a dial indicator to measure the amount pier pulls out at load increments- the capacity is not typically taken (factored off) from the point of failure but off an allowable deformation
@@c4fishfood Well, if you only use 50% of the breaking force, knowing that a push down test would bring you even higher values, I think you are on safe grounds (pun intended). By the way, due to windforces thath can easily carry away a wooden Gardenhouse, knowing the amount of "pull" that these screws can take is important too.
Jörg Schulze The problem is more to do with the consequences in the case the screws hit or exceed their rated load, and you are not able to determine that from purely the applied load on a pull test, needs to be measured in combination with deformation. It may not be a problem for a “garden shed” but this building could very well be built no different than a house. What’s the point of doing the test if not done right? I’m not pulling this out of my ass, it how the proper test are specified. Also, I agree that the uplift capacity might be required (earthquakes control uplift load where I’m from)- I was just responding why the test in the up direction is able to be used to estimate bearing capacity. The real reason it is done in that direction is that it is easier to pull a screw pile than to push it.
This has to work in the right soil conditions. Seems like these could be frustrating in certain circumstances. Nice system otherwise. Like an auger for deck footings. I did most manually because its like 50 50 that its worth it. Although the pilot hole prob makes a big difference. Cheers. Good vid
You're measuring the resistance of 1 screw but that would be the weight through that 1 screw. However, if you add further screws wouldn't that in effect share the weight bearing load?
Perhaps the best thing about this system is that you can remove them and not leave blocks of concrete. Still worried about hitting rocks though. - maybe drill and bond in rebar for those.
I'm guessing a site survey is required prior to screws going in to make sure no services are below. Does the company you hired do this? If something is damaged, i.e drainage, does the company take ownership of this or is this the responsibility of the contractor?
The first question I ask any potential client is whether there are any services running through the site. In most cases the builds are at the back of the property and unlikely to have any services. If I'm in any doubt I use www.linesearchbeforeudig.co.uk/ to get maps of all the services and what they might be. I have a CAT scanner to locate any power lines and I can hire a flexible rod sonde and generator to locate drainage pipes. Gas mains are a different matter and if they show on the maps, I'll make the client aware which can hold up the installation until they are pin pointed. The beautiful thing about using screws though, is once the services are located, the network of screws can be plotted to avoid them with no loss in integrity to support the structure. I'm also insured up to £10 million for public liability.
@@gilschaeffer5522 Thanks for taking the time to reply Gil. Could you elaborate on the costs for the screws and are you a nationwide company or just based down south.
@Abs Kan the sub-contractor that installed the screws for our garden office used a cable avoidance tool prior to setting out, plus I worked in a utility and anticipated questions about service runs and was able to describe routes of all services.
@@abskan4015 That was a little bit sneaky my friend. Perhaps you could elaborate on your costs for your screws and where you're based? I hope you're keeping busy?
Yes, indeed! I've made many extension "wings" here in Scandinavia with screw poles! Until the soil is suitable (forest field without roots) it's more than easy to drill poles to the ground and build logs on the poles!
Come on Robin, your promoting the ground screws and the hiding the costs . Screws?, install, total???? Great video thanks for the time in putting it out. Loved the cleft fencing to.
The cost was about £100 per screw installed, this can vary on quantity, length, location etc, no paid promotion in this video!! I really like this solution thanks for your comment Grant
Revolutionary......Most Very cool.. It would be fun to be a part of this kind of installation. Where did you get the screws - From our American politicians?
Hi Murad, thanks for your question about my square, I have the first 10 prototypes being produced in the next 10 days these are for my testing etc, the app calculators are coming on and I am creating tutorial video, it's taking a little longer than I would have Hoped but I want it to be right, hope, have a good weekend mate, all the best Robin
Pull test needs to be spread over a larger area otherwise the soil is being compressed between the testing rig and the pressure bulb created by the screw.
I did wonder about that too. The footprint of the hydraulic test rig seemed to be quite small given the load applied. I wondered if the load would cause compression and distortion of the surface under the test rig so rather than pulling the screw out, it would tend to pull the test rig into the surface. Maybe use some form of plates under the test rig footing to spread overall load per unit area? The prepared surface looked pretty robust though, even if the ground is essentially clay of some description. Maybe Type 1 is used to distribute some load? Very interesting though.
@@protectiongeek it is ideally done over three reaction piles using beams to span over the pile you want to test so the pressure bulbs from each do not interact with the one being tested. Maybe they use a factor on the read out other then the safety factor which is typically 2:1 or 2.5:1. The theory is if it can resist an axial force in tension it can resist the same in compression. 👍
Hi Isaac, it worked out a fraction of the cost of doing a ground bearing reinforced raft for this project, this building was over 30m2 and this then needs to be built to the same standards as a proper new build including full building regulations and structural calculations, it is not as simple as just doing a concrete base here as we are on clay and a proper raft would have costs about £15k - £20k our screws where about £3k from memory and then the timber sub floor and ring beam was probably about £4k so significantly less hope that helps
Hi, I like these for poor access jobs, but can’t see how they cost effective against a 3ton machine for day/2 tips. To pull out rubbish and get a raft concrete floor slab in??? How much is it per screw? Cheers
We costed a raft and with the structural engineers fee for the calculations to make this acceptable to the building inspector, the groudworks, shuttering, reinforcement, concrete and muck away would have been 10 times the cost of the screw piles, we investigate and evaluate the best and most economical solutions for our clients also we have an eye on the impact of our builds, screws are absolutely perfect for a temporary structure such as a garden room or home office
@@ukconstruction Previously the cost was about £100/screw = £2,100 approx. Are you saying a concrete slab would have cost £20,000?!! Thanks for the vids, very interesting!
Hi Robin, would you say this particular screw system could be used to build a timber frame room and house my full size snooker table. It’s currently at my parents house in a conventional building I built with solid concrete floor. Looking to re-house it at my new place. Total weight 1250 kg but weight per legs x 8 is 160kg. Obviously calculations for room weight yet is unknown. Thankyou.
Hi Gary, It all depends on the ground mate, where are you based? if the ground is good then yes its totally adequate, for the snooker table you would simply stiffen the floor structure locally and have some additional screws in that position Hope that helps mate
@@ukconstruction Many thanks for your quick reply. In Surrey on chalk. Trouble is no side access anymore, I just finished big wrap around extension but gotta move table. Looking for less aggro on oversite. But need to build very soon. May be in touch.
@@ukconstruction Thanks for your reply, I have a few questions - hope you don't mind them. With the grounds shifting and soil moving over the years.... 1. How long will these screws last? 2. How does the screw hold itself in a fixed area? Will it not sink down etc? as soil moves over the years 3. Will the base be strong enough to support the load of a shed which will contain heavy gym lifting equipment? Thanks in advance.
Hi Greg, we did this install in one day, we had a couple of problem screws that held things up but apart from that it was pretty quick, the screws have been used here in the UK for probably 10 years in various forms and probably longer elsewhere in the world, good to see you last week, my lawn is looking much better now you have done your magic mate!!!
A concrete slab that is engineered not to fail and meet building regulations for this build would need to be a proper reinforced raft and it would cost well over 10k maybe even 15k
@@ukconstruction Robin, you're not comparing apples to apples. With screw piles you need to include labor and framing materials for the subflooring. There may be some savings, but not much. A simple slab can be formed and poured in a day. I don't like that there's air gap below the structure - easy access for critters to get at insulation.
Try getting that proved and past the building inspector, any garden room or home office over 30m2 needs to comply with building regulations that are the same as a dwelling
I'm doing garden room under 30m2 and under 2.5m tall. Dug 15 of 900mm deep holes by 300mm cylindrical shape and had concrete pumped in. Building is on stilts fixed into these concrete piles.. hopefully that should be ok. Hard work to dig by hand in the clay.
No indeed, from our tests the bearing capacity is considerably more in most ground conditions than the readings that we ascertain from this pull test, but we have a formula from our pull test to compute the potential bearing capacity and then for working out suitable loadings per use a 50% safety factor for example if we work out that a screw can take 3 tons of weight we only would apply a loading of 1.5 tons
These seem like a great alternative to concrete!! I've seen guys digging holes and setting screwed rod into individual concrete founds but this is even better. Does each screw require the pull test?
Unless I'm way off the mark you definitely wouldn't do that. You are testing the screw to failure (the ground is unable to exert enough force on the screw to keep it in place), once you've done that, the ground will be loosened and no longer able to hold the screws as well.
I dont understand why you do a pull test on something which wont receive any pulling force. Rather you dont want them to sink into the ground under the pressure of whatever your building ontop
When you said you have a 50% safety margin had you been advised by the manufacturer or a structural engineer that the pull up test is subject to a 50% safety margin.
We do this so we never give too much load to an individual screw, our own structural engineers always apply a safety factor to nearly every structural element be it a beam or column etc, it's just good practice.
Wind loads pull the foundation up so you need some resistance to uplift, but pulling is a reasonable test for compressive loads because of how the screws work - the load (pulling or pushing) is transferred to the soil by the screw thread and the soil has the same resistance to movement whether you pull up or push down.
And the test should and likely does error on the conservative side. Meaning the screw's resistance becomes stronger the deeper it is founded and weaker once it is moved upwards in the ground.
@@ukconstruction are the installation tools available to rent? If I had to pay a subcontractor to install I can't see any saving, and is this method accepted by building control?
They work in a just about all soils. In the 3 years I've been installing them, I've only failed 3 times. One the site was pure hardcore. The second was newly made up earth. The last was solid Chalk from a depth of just 500mm. I could pilot the holes after a lot of swearing but the screw wouldn't go any deeper than 500mmm. I'm getting some smaller screws to deal with this situation.
Thanks for joining me on the live chat guys, I have just refreshed my page and you have all disappeared so apologies for not signing out!! I am still getting use to tech and all this UA-cam stuff!! I had better stick to carpentry!!
Robin is the king of the big screw.
Hi Robin Thanks for your reply, could I just add. For the client any building work comes as quite an intrusive shock to most of them and having a lot of builders thrashing around can be very distressing for them, as they don't always envisage what is going to be involved, for some rather than being an exciting time it can be very upsetting. I never let any one on my jobs rush around or go any where they are not supposed to be an to show respect to the client at all times. I think that these screws lessen the impact for the client and make it a more enjoyable experience and that has to be good and they keep the the mess down for a better environment to work in. Great work as always Robin, tough times at the moment.
Hi Robin. I work at a builders merchants in the North West. Another company that installs groundscrews came in and spoke to me about them. It was the first id heard about these and I was blown away. Great idea instead of concrete.
Which merchants?
What a brilliant idea. I bet the ready mix concrete companies are fearful of this. Good video. 👍
Hi Robin, What I like about this form of construction it is a lot less invasive and you haven't got all that spoil from foundations. Makes for a nice neat job as always.
I totally agree!
Looks good. You didn't show us the raw plugs for the ground screws mate
It would be quite the task pulling them bad boys apart!
You only need the plugs if your going into concrete
Excellent video, thanks Robin. We had a garden office pod built last year. Roughly 5m x 4m footprint, used 12 ground screws. Setting-out and installation took about 4 hours start to finish so construction of the structure could start next day. Very impressive form of foundation.
We are in discussions with our architect about a rear extension to our house (approx dims 7m x 4m) and have asked her to speak to the engineer to see if we can use ground screws for that too. Saves a lot of time, money, disruption and CO2!
I do like the US system. Drill a large post hole, drop in a cardboard tube straighten it and level the tops. Fill with concrete and job done.
I'm surprised that you can't buy Sonotube or similar in the UK.
Great video! Didn't even know these things existed. I'll go for this for the new workshop than laying a slab.
Ive used these on solar PV ground mount system in the past. Quick and versatile and can be removed if so required with minimal fuss and wastage
Just crossed my mind as we that these could be used as part of the electrical installation. The screws could be used as a multi rod TT earthing system.
As long as they remain conductive after their surface finishing process. Anodising for example produces a non conductive surface.
Those are actually really interesting! First I’ve ever seen but glad I know they exist 👌🏼⚡️
It's like Land of the Giants!
I remember something similar on a DIY SOS many years ago. They used impact to screw them in, but had to wait for a flint wall they were building to harden because the vibrations were causing it to settle.
Hi Robin, I’ve just built a cabin in my daughters garden i used 28no 750mm screws all put in by hand, very good idea but hard work by hand that drill set up makes it look like a doddle thanks for the vid 👍
Oh... and looking forward to seeing what a 40 tonne garden room looks like.
A small suggestion is that you can connect the grounding cable of your house from these nails and secondly, all nails should have a communication cable between each other And add an anode to prevent all this from being affected by static electricity
I keep thinking that this is a Jackman Works video because of how big those screws are. Lol. Those are a nice bit of kit.
They look like a great idea. I don't know if they would use it in Australia but it would definitely save some time.
Hi Robin cracking video, the screws are a cool idea quick and easy foundation and very cost effective I would assume look forward to the next phase, quick question who signs them off engineer or the screw company all the best Tony 👍 have awesome weekend
Hi Tony, these get signed of by building control based on the pull tests and our overall loadings etc, have a great weekend to mate, all the best Robin
Absolutely fascinating Rob looks awesome 👌👌
The caveats near the end are important. In my project I had heavy clay and it wasn't possible to drive some of the screws very deep even with that massive torque arm, so some of the screws were swapped to shorter versions. Plus we hit rocks. When you hit a rock you're a bit screwed (no pun intended), because you've already disturbed the ground, and you really want that position, so what do you do? The end result was screws not perfectly located and/or not perfectly plumb, which was time consuming to correct for (I fabricated some ugly but strong epoxy mortar shims). Now the level of professionalism of the installers wasn't as high as is evident here, but the lesson is: design so that you can cope with slight variations in position. I think if I ever do another similar project I'll just pour concrete piles. I think these screws work best when you have deep but workable subsoil.
Heavy clay isn't too much of an issue, it can be overcome by either pilot drilling with an earth auger or by taking a measurement to see how high that groundscrew is sitting. That screw then gets removed and cut shorter - if you haven't got a shorter screw that can be used. As the ground has been disturbed, the hole gets filled with 10mm gravel and the groundscrew driven back in. The gravel acts like a rawlplug, it gets compacted into the ground around the screw giving it good purchase. A pull test will confirm that its well in.
Yes, the "ruined" soil can be fixed with a smal stone mix. Take the pole out and pour the small rocks on the hole, then put the screw back and redrill! Quarantine solidity as original 😊
Use the chicken leg 😂
@@Dragon-Slay3r ???
Hi Robin, Great video, I’ve just looked into using these here in Australia for a deck I’m going to be building. The are quite cost competitive when compared to digging or using a post hole digger, disposing of the soil, concrete delivery and concrete pump, and all the labour associated with this. Ground Screws can be done easily in 1 day, and saves a heap on my 50 year old back.
They don't do these up b&q in the screws section. I looked everywhere.
They do I found some but they they we’re only suitable for very some buildings they were 2 inch 8 screws
is that loading requirement per screw? or for the whole structure ? ie 2000kg per screw ?
Great product, not so sure they would work in Ireland with the amount of large field stones in the ground.
My project was in Ireland, see my more recent comment further up. They can work, but they're not easy.
Looks like a little piece of Heaven .
That's almost as strong as a punch from Ivan Drago!!!!
Amazing!!!
Thanks for sharing. With the weight of building structure sitting on ground screws, wouldn’t of thought you need to be concerned about pulling screws out, more if the sink in the ground under the loading. Back to front test I think.
For wind loading I would guess, cheers
Looks more expensive than concrete! How does it compare?
What about a ground survey to both determine the suitability of the ground and to ensure you don't screw into 'anything important' like drains, pipes, cables, etc?
Hi Simon, we use a ground scanning device when we have no record of services etc, we also know before we start what the local geology is by an app
@@ukconstruction that app sounds interesting Robin. Would you be able to share what it is please?
Now how do you attach it to the frame???? Not one video on youtube shows you how to do it
What's the point of the pullout test. The screws are not subjected to a tensile force. You would need to undertake a static axial load test. Add some kenteldge and see if the screw settles
Nice Robin saves all that concrete, not too mention the digging would of been nice of you to introduce the guys doing the screwing, keep up the great videos 👍
Oooh matron.
What’s the point of the pull test. I would be more worried about the possibility of sinking than the building levitating off in to the air.
A pull test can be used to measure the compressive capacity as well. Typically a tension test will give a lower value, but the load in either direction is primarily a function of the engagement/contact area of the threads and the strength of the soil. The reason a pull test comes out a bit lower is you may get some extra capacity from the end bearing of shaft when pushed down.
That said, their test was meaningless. They should have used a dial indicator to measure the amount pier pulls out at load increments- the capacity is not typically taken (factored off) from the point of failure but off an allowable deformation
@@c4fishfood Well, if you only use 50% of the breaking force, knowing that a push down test would bring you even higher values, I think you are on safe grounds (pun intended). By the way, due to windforces thath can easily carry away a wooden Gardenhouse, knowing the amount of "pull" that these screws can take is important too.
Jörg Schulze The problem is more to do with the consequences in the case the screws hit or exceed their rated load, and you are not able to determine that from purely the applied load on a pull test, needs to be measured in combination with deformation. It may not be a problem for a “garden shed” but this building could very well be built no different than a house. What’s the point of doing the test if not done right? I’m not pulling this out of my ass, it how the proper test are specified.
Also, I agree that the uplift capacity might be required (earthquakes control uplift load where I’m from)- I was just responding why the test in the up direction is able to be used to estimate bearing capacity. The real reason it is done in that direction is that it is easier to pull a screw pile than to push it.
Or more like shear loads. Would be one heck of a bracket sleeve to hold a 6' fence up. Very cool anyways.
@@gulashonu Agreed- these small diameter screws do not have a very good lateral load capacity unless tied together to work as a group.
What is the cost of the screws & do they come with any warranty 👍🏻
Long screws are great!
This has to work in the right soil conditions. Seems like these could be frustrating in certain circumstances. Nice system otherwise. Like an auger for deck footings. I did most manually because its like 50 50 that its worth it. Although the pilot hole prob makes a big difference. Cheers. Good vid
I think the supports for Brighton Pier were screwed in by this method , Over a hundred years ago?
What are the machines that are used to put them in? Where can you get those and the screws?
Your hair's looking cool man! I will refrain from any screwing jokes...
You're measuring the resistance of 1 screw but that would be the weight through that 1 screw. However, if you add further screws wouldn't that in effect share the weight bearing load?
How do you deal with tree roots and underground services
Perhaps the best thing about this system is that you can remove them and not leave blocks of concrete.
Still worried about hitting rocks though. - maybe drill and bond in rebar for those.
Very interesting!
Great video. Proper cheesy ending!
over the top ,
How much will cost me if I'm doing myself with friends on 10 X 6 shed
Hows things , have you any update on your roofing square yet ?
Hi there. Where to buy the ground screw driver?
How low to the ground can you top of the screw piles?
The ground screw tested will hold more after 24hrs after installation as the water pressure induced to the soils during installation settles again.
Great video thanks
I'm guessing a site survey is required prior to screws going in to make sure no services are below. Does the company you hired do this? If something is damaged, i.e drainage, does the company take ownership of this or is this the responsibility of the contractor?
The first question I ask any potential client is whether there are any services running through the site. In most cases the builds are at the back of the property and unlikely to have any services. If I'm in any doubt I use www.linesearchbeforeudig.co.uk/ to get maps of all the services and what they might be. I have a CAT scanner to locate any power lines and I can hire a flexible rod sonde and generator to locate drainage pipes. Gas mains are a different matter and if they show on the maps, I'll make the client aware which can hold up the installation until they are pin pointed. The beautiful thing about using screws though, is once the services are located, the network of screws can be plotted to avoid them with no loss in integrity to support the structure. I'm also insured up to £10 million for public liability.
@@gilschaeffer5522 Thanks for taking the time to reply Gil. Could you elaborate on the costs for the screws and are you a nationwide company or just based down south.
@@abskan4015 please email me at info@gravitasgroundscrews.co.uk and I'll answer all your questions. Cheers!
@Abs Kan the sub-contractor that installed the screws for our garden office used a cable avoidance tool prior to setting out, plus I worked in a utility and anticipated questions about service runs and was able to describe routes of all services.
@@abskan4015 That was a little bit sneaky my friend. Perhaps you could elaborate on your costs for your screws and where you're based? I hope you're keeping busy?
I thought I was watching, Honey i blow up the screws!
It’s like the borrowers at 4:30.
What is the cost of this technique please? Plus over a 40ft length I have an elevation of 1ft. Could the screws be used to level my ground plate?
Can this method be used as a foundation for a one story wooden house extension ?
Yes, indeed! I've made many extension "wings" here in Scandinavia with screw poles! Until the soil is suitable (forest field without roots) it's more than easy to drill poles to the ground and build logs on the poles!
Did the skinny chap do any work all I saw Gill doing it all
Hi, I'm wanting to put a good strong shed/garage down, but i have bedrock where i want it. I'm in cumbria. Can these be used for my shed? Thanks
Possibly Scott, can you not build straight off the bedrock with class 4 timber??
Do these work in chalky ground?
Could you do block and beam off these screws?
Maybe too heavy
@@ukconstruction shame, I have some mature trees close by and want a Solid floor, piles will be pricey
Come on Robin, your promoting the ground screws and the hiding the costs .
Screws?, install, total????
Great video thanks for the time in putting it out.
Loved the cleft fencing to.
The cost was about £100 per screw installed, this can vary on quantity, length, location etc, no paid promotion in this video!! I really like this solution thanks for your comment Grant
Revolutionary......Most Very cool.. It would be fun to be a part of this kind of installation. Where did you get the screws - From our American politicians?
Any news on the roofing square? Keep up the great work Robin. 👍
Yeah I want to know aswell I won’t buy a new one until I here about his he is releasing
Hi Murad, thanks for your question about my square, I have the first 10 prototypes being produced in the next 10 days these are for my testing etc, the app calculators are coming on and I am creating tutorial video, it's taking a little longer than I would have Hoped but I want it to be right, hope, have a good weekend mate, all the best Robin
Awesome. Hope it goes well mate. 👍👍
Pull test needs to be spread over a larger area otherwise the soil is being compressed between the testing rig and the pressure bulb created by the screw.
I did wonder about that too. The footprint of the hydraulic test rig seemed to be quite small given the load applied. I wondered if the load would cause compression and distortion of the surface under the test rig so rather than pulling the screw out, it would tend to pull the test rig into the surface. Maybe use some form of plates under the test rig footing to spread overall load per unit area? The prepared surface looked pretty robust though, even if the ground is essentially clay of some description. Maybe Type 1 is used to distribute some load? Very interesting though.
@@protectiongeek it is ideally done over three reaction piles using beams to span over the pile you want to test so the pressure bulbs from each do not interact with the one being tested. Maybe they use a factor on the read out other then the safety factor which is typically 2:1 or 2.5:1. The theory is if it can resist an axial force in tension it can resist the same in compression. 👍
Do they meet NBC Canada and USA?
I have no idea??
Can these be used for ‘permanent’ structures or just for outbuildings like your doing here?
Amazing
How much does this system cost ? For a large garden room area ?
Hi Isaac, it worked out a fraction of the cost of doing a ground bearing reinforced raft for this project, this building was over 30m2 and this then needs to be built to the same standards as a proper new build including full building regulations and structural calculations, it is not as simple as just doing a concrete base here as we are on clay and a proper raft would have costs about £15k - £20k our screws where about £3k from memory and then the timber sub floor and ring beam was probably about £4k so significantly less hope that helps
Hi, I like these for poor access jobs, but can’t see how they cost effective against a 3ton machine for day/2 tips. To pull out rubbish and get a raft concrete floor slab in???
How much is it per screw? Cheers
We costed a raft and with the structural engineers fee for the calculations to make this acceptable to the building inspector, the groudworks, shuttering, reinforcement, concrete and muck away would have been 10 times the cost of the screw piles, we investigate and evaluate the best and most economical solutions for our clients also we have an eye on the impact of our builds, screws are absolutely perfect for a temporary structure such as a garden room or home office
@@ukconstruction Previously the cost was about £100/screw = £2,100 approx. Are you saying a concrete slab would have cost £20,000?!!
Thanks for the vids, very interesting!
What is the name of the screwdriver?
Hi we have the rock hard clay but we have a high water table and it's coming up from the ground, would these screws work still for a log cabin base?
Absolutely they are galvanised and durable, I use them in Clay all the time, and our clay is very hard
Hi Robin, would you say this particular screw system could be used to build a timber frame room and house my full size snooker table. It’s currently at my parents house in a conventional building I built with solid concrete floor. Looking to re-house it at my new place.
Total weight 1250 kg but weight per legs x 8 is 160kg.
Obviously calculations for room weight yet is unknown.
Thankyou.
Hi Gary, It all depends on the ground mate, where are you based? if the ground is good then yes its totally adequate, for the snooker table you would simply stiffen the floor structure locally and have some additional screws in that position
Hope that helps mate
@@ukconstruction
Many thanks for your quick reply. In Surrey on chalk. Trouble is no side access anymore, I just finished big wrap around extension but gotta move table. Looking for less aggro on oversite. But need to build very soon. May be in touch.
Guys where can I buy this Drill to screw it into the ground?
Can you put ground screws in soil or does it have to be cemented floor?
Yes, we can screw into most ground and soils
@@ukconstruction Thanks for your reply, I have a few questions - hope you don't mind them.
With the grounds shifting and soil moving over the years....
1. How long will these screws last?
2. How does the screw hold itself in a fixed area? Will it not sink down etc? as soil moves over the years
3. Will the base be strong enough to support the load of a shed which will contain heavy gym lifting equipment?
Thanks in advance.
How long did that lot take Robin? From setting out to last screw installed?
Have these mammoth screws been around for a while?
Hope you’re well mate.
Hi Greg, we did this install in one day, we had a couple of problem screws that held things up but apart from that it was pretty quick, the screws have been used here in the UK for probably 10 years in various forms and probably longer elsewhere in the world, good to see you last week, my lawn is looking much better now you have done your magic mate!!!
If that cost £2100 for the screws how much would the equivalent concrete slab cost?
A concrete slab that is engineered not to fail and meet building regulations for this build would need to be a proper reinforced raft and it would cost well over 10k maybe even 15k
Where did you get £2100 from bud?
Fredrick Welch I’m assuming he’s priced them at £100 each and robin says he’s using 21 screws😁
Fredrick Welch - yep 21 at £100 each
@@ukconstruction Robin, you're not comparing apples to apples. With screw piles you need to include labor and framing materials for the subflooring. There may be some savings, but not much. A simple slab can be formed and poured in a day. I don't like that there's air gap below the structure - easy access for critters to get at insulation.
What's the design life on the screws?
We guarantee them for 25 years against corrosion, but in reality they should last much longer. They are also removable and reusable.
Just need to develop a 'ground nail' now, with an enormous hammer ,a ring shank wouldn't pull out easily😁
These screws are just standard 3" screws. They just used 2" tall actors to play the builders to make the screws look bigger.
How much did that cost for what was included in the video?
Looks like £100 a screw so £2100
your hair is so beautiful. Who is your hairdresser,
What shampoo do you use?
It looked like a scene from the incredibly shrinking men using normal screws!
surely its cheaper to dig the holes + fill with concrete then fix to that ?
Try getting that proved and past the building inspector, any garden room or home office over 30m2 needs to comply with building regulations that are the same as a dwelling
I'm doing garden room under 30m2 and under 2.5m tall. Dug 15 of 900mm deep holes by 300mm cylindrical shape and had concrete pumped in. Building is on stilts fixed into these concrete piles.. hopefully that should be ok. Hard work to dig by hand in the clay.
@@adamandlorraine I did that with mine. Dug to solid ground, concrete then brick pillars. No moment at all.
Extravagant
Uplift resistance does not equal bearing capacity. Just thought you should know.
No indeed, from our tests the bearing capacity is considerably more in most ground conditions than the readings that we ascertain from this pull test, but we have a formula from our pull test to compute the potential bearing capacity and then for working out suitable loadings per use a 50% safety factor for example if we work out that a screw can take 3 tons of weight we only would apply a loading of 1.5 tons
What's the name of the company you use?
Gravitas Ground Screws. Here is the link to my facebook page facebook.com/GravitasGS
Is this 2 tonne for each screw or for the whole build? What's the cost for this roughly compared to a concrete foundation
Each screw, far cheaper than a concrete raft which is what we would need to meet building regs etc
just put a plastic grid down fill with shingle . put 4/5 small anchors in job done half the price
These seem like a great alternative to concrete!! I've seen guys digging holes and setting screwed rod into individual concrete founds but this is even better.
Does each screw require the pull test?
Unless I'm way off the mark you definitely wouldn't do that. You are testing the screw to failure (the ground is unable to exert enough force on the screw to keep it in place), once you've done that, the ground will be loosened and no longer able to hold the screws as well.
you need to start talking about prices when you do these videos rob.
I reckon that testing device could open my mates wallet, lol. Very interesting film, cheers guys.😀👍👏
I dont understand why you do a pull test on something which wont receive any pulling force. Rather you dont want them to sink into the ground under the pressure of whatever your building ontop
Wind load
@@richardcapey-wade8191
The wind may lift up the structure???
Expensive....!!
When you said you have a 50% safety margin had you been advised by the manufacturer or a structural engineer that the pull up test is subject to a 50% safety margin.
We do this so we never give too much load to an individual screw, our own structural engineers always apply a safety factor to nearly every structural element be it a beam or column etc, it's just good practice.
Pull test for something working in compression?
Wind loads pull the foundation up so you need some resistance to uplift, but pulling is a reasonable test for compressive loads because of how the screws work - the load (pulling or pushing) is transferred to the soil by the screw thread and the soil has the same resistance to movement whether you pull up or push down.
And the test should and likely does error on the conservative side. Meaning the screw's resistance becomes stronger the deeper it is founded and weaker once it is moved upwards in the ground.
Looks a great product, but you'd have to be certain there were no services bellow.
We do a site survey with a device for locating any services as you mention, thanks for your comment
@@ukconstruction are the installation tools available to rent?
If I had to pay a subcontractor to install I can't see any saving, and is this method accepted by building control?
For a shed
more likely a garden office for someone like me who will be working from home for the foreseeable.
@@TheSudsy ld probably refer to qualified people for your application
Suitable for clay only .
They work in a just about all soils. In the 3 years I've been installing them, I've only failed 3 times. One the site was pure hardcore. The second was newly made up earth. The last was solid Chalk from a depth of just 500mm. I could pilot the holes after a lot of swearing but the screw wouldn't go any deeper than 500mmm. I'm getting some smaller screws to deal with this situation.
Gil Schaeffer In that case they’re a great solution .