Very helpful! Thank You for your time and for covering all the aspects I needed to gather materials , tools,, and plan the repair of my roof issues . I particularly appreciated you sharing the affects and having to plan for PSF of up-lift! Great video. Never unestimate the power of sharing knowledge and experiences . It is a raw form of caring about others! Thank You again!
Excellent and informative video. Thank-you once again Jack. Years ago I installed metal roofing on my garage and a wrap around verandah with the screws placed on the peaks but now I'm starting to see signs of moisture around the screws on the underside of verandah roof so I agree that the valleys would have been better. Also, on the verandah I was screwing the top half of the panel and my dad was securing the bottom half. He tended to apply a bit more screw pressure which would flatten out the peaks a bit more than mine, deforming the panels into a wedge shape. After 6 sheets it became quite apparent we were no longer running parallel and had to remove and redo the panels. Make it nice or do it twice. With time I suppose the rubber washers shrink and harden and with the expansion and contraction of the sheets, it creates more movement at the screws when they are placed on the peaks. The expansion and contraction would explain why the manufacturers only have one screw in the valleys, allowing the raised portions (peaks) to soak up the movement. Live and learn. Sorry, this is becoming a long comment, but I have a question you may be able to help me with. We had local tornadoes this past spring and many farms and homes lost their roofs as well as downed trees. Luckily my roofs were ok. The original house has the ridge going in one direction and a later addition has the 2nd ridge going 90° to the first. So the wind was hitting a gable face on one portion while it rode the surface (like the airfoil you described) on the other. X and Z axis on your simulation model. I only noticed a day later, but the attic access panels for BOTH attics actually got sucked up into the two separate attics. Pretty scary to realize we may have just been on the edge of losing the roofs. So here's my question. Going back to the analogy of the roof becoming an airfoil, I'm not able to decide if the sucking in of the attic access panels was a good thing or not. I'm thinking it ended up increasing the pressure in the attic, thereby increasing the "lift". In other words, the access panels should maybe be secured down in some way, not simply dropped down into place. What is your thought, or if anyone else has insight into this, I would appreciate comments. Did the openings relieve a negative pressure or increase the pressure in the attics. Thanks again.
I should also mention the original portion of the house was built in 1910 and the addition around 1918. The soffits are closed with tongue and groove and not properly vented like todays construction. Plus on the 2nd floor, the rooms have slanted walls (the roof), again not providing proper air flow. I have vents at the gable ends to provide air circulation. This no doubt added to the negative pressure in the attics.
Wish I'd seen this fifty years ago when I was working on a pole barb building crew. Lots of leak repairs. Now I realize it was over-driven screws (or maybe it was nails back then) , not simply that they were driven into valleys. Even now (until today), I've used wiggle wood and screwed through the peaks on Fiberglas deck roofings and the like. Thank you, Jack, for making the rest of my life simpler.
Great video - thanks a lot. The roof on the building which I bought is scratched in some places. Is there a way to protect the metal roof to extend its lifespan by for instance repainting it? Any advice would be appreciated 🌹
Awesome video, my metal roof is 12/12 pitch, on SIP panels, very well insulated no heat lost what so ever. The biggest problem we get living here in Atlantic Canada is the winter freeze thaw cycles. The snow will not slide off the North side of the roof and when it thaws a bit and freezes again it forms around the head of the screw creating a solid sheet of ice on the roof, it’s impossible to get it off with any conventional tools. We have to wait untill spring and the melting cycle. Sometimes when the melt is slow there is an overhang at the edge where the ice slowly slides down getting 4ft or more of overhang before it brakes off with a thunderous crash. My suggestion to your viewers living in snow areas is to use the hidden screw type roofing, my neighbours went that route and have zero issues with ice hanging onto the screw heads.
Agree, standing seam roof, or the new style that mimics it with hidden clips/fasteners, is really ideal for areas with a lot of snow. Just be very careful with penetrations for vents, vent pipes, chimneys, etc, to make sure they have a proper diverter, skirt, and flashing, otherwise the sliding snow will tear things apart and cause leaks and damage. And there are certain parts of a roof where slides could be dangerous for what's below, so snow guards / stoppers might be needed to retain snow in those locations. I know a few people that installed this type of roof and later had to go back and add diverters and snow guards to control what the snow does. Luckily they caught it early before significant damage happened. In bad situations, I've seen it peel open the roof and cause a major issue. A heavy snowpack has a lot of power when it starts sliding. Luckily with a SIPS construction, you aren't going to lose any heat through the roof. That can be an additional concern in some climates, where you get additional freeze/thaw issues from heat rising through the roof. It's a hard balance to get right.
Screwing on the rib adds back tension to the rubber screw seal. However, if attaching to furring strips, most screw on the flat for strength of attachment. My rule of thumb is, if you’re installing on solid decking, typically new construction or a complete roof rebuild, screw on the ridge. If you’re installing metal roofing on furring strips over an old roof, screw on the flat to get deeper penetration & additional rigidity of install on the roof. I could be wrong. Some do both the rib at overlap, & the flat everywhere else.
I spoke to a rep for one of the big metal manufacturers about 3 weeks ago and the conversation wandered to this topic. He said they advise against screwing on the ribs primarily because it deforms the panel profile and compromises sealing of the screw washers. The only panel in their product line that is suitable for screws on the ribs is 26ga PBR panel.
What an excellent informative video. I’m planing on doing our 24x24 detached garage. It’s 15 years old and the asphalt shingles starting to fail. Here in Ontario Canada, it seems that as per the manufacturer of local roofing steel, the ribs are the preferred location for the fasteners. I will be doing 1x4 strapping on top of the existing shingles for the new metal roof. I am debating what gauge of metal to use as I have the option of 29 or the heavier 26 gauge. I am also debating if I need to cut a ridge vent since this is an unheated detached garage with nice wide aluminum soffits. Since I have 2 x 4 blocking in between the roof trusses at the peak, cutting a ridge vent doesn’t seem to serve much purpose. I would like your thoughts on what gauge of metal I should use and if I need any vent at the ridge in your honest opinion, thank you
From the 12 minute mark where the dots are showing where to put the screws, what if you don't have that many studs going across in the middle to put the screws in? You would have to have 4 horizontal beams and yet only two vertical beams to make a grid support, not including the top and bottom support. I'm using boards underderneath. Maybe that's what was used. I am used to seeing grid supports. I know I am not using the correct carpentry terminology but I think you probably will understand. Thank you!
That roof has rafters every 2 feet and purlins every 2 feet, so it's a 2' x 2' grid basically. The number of fasteners and pattern specified by the roofing manufacturer is mainly setup for panel retention under wind uplift loads. Fewer fasteners means less uplift resistance. And that translates down through the framing as well. The screw loads holding the panel to the purlins must be handled by the purlin-rafter fasteners and the rafter-header fasteners along with any storm clips. And so on down to the posts and footings. Everything is connected and important. Skimp somewhere and the roof will have less uplift resistance and be more likely to peel off under wind loads.
I suspect there are shapes/modifications that could reduce uplift loads on roofs. However, it may be impossible to make it work for every possible wind direction coming towards a structure. You could likely optimize it for a certain onset wind direction though.
Hey thanks for the info. I've got a question for you. My house is about 30 years old and we are a couple kms from the coast with high winds. The colourbond is ok but the heads of the screws (12g 50mm) are quite corroded. My question is, should I replace the old screws with screws of a greater diameter or length? Also, are longer screws used for the ridge caps?
Normally the ridge cap does use longer screws if you need to reach into the framing below. But on some installs the ridge cap is only attached to the metal sheeting, with short self-tapping sheet metal screws. So you need to know how the original install was done to know what sort of screws are used at the ridge. I have replaced screws on an older roof a few times and always use the same type and length screws, but of course the new screws were about 25-30 years newer and have better material for the gasket and a slightly different washer shape (to protect the gasket from the weather better). I would not deviate on screw diameter and length, but finding screws with a larger/better cap and gasket can only be an improvement.
Can you use self tapping screw to attach it to wood, 1x4 or 2x4 or plywood on the roof? It would be easier than predrilling at some places, also get cleaner and flat hole on the metal sheet, also easier to keep in place once starting to drill.. But would the screw hold any worse than regular screw in the wood/ plywood?
No, they don't have the right kind of threads, and won't have very good retention in the wood. Screw retention figures prominently into loads and uplift resistance and is very important for roof performance.
Great and informative video. Metal roofs get a bad rap because of poor installation. A properly installed metal roof should be the last roof you ever have to put on your house.
Good video but, this would be great info video for me if you showed the exact metal roof and screws I used, like the metal roofing HD sells. HD sells several types but I bought mine from nearby lumber yard that sells the same as HD..... All your charts showed perfectly flat tops or rounded, why didn't you show the common metal roofing HD sells, the top/peaks aren't perfectly flat nor are they rounded, theres a water channel on the tops with very slight curvature on the very top of the peak. It's a very common panel, there really no room for tape on the tops but calking could be used, which I thought of doing but didn't. Then the screws you showed, ALL have perfectly flat washers, never seen that type, the ones I bought have a dish shape washer that covers the gasket lot better...... Then why didn't talk about roof pitch needed for screw type metal roofing, I spent 10 hrs this past August looking online trying to fine answers to that, which I thought would only take 5 min....... So on my shop that was built 10 years ago, I thought it was lot harder to screw panels that way, constantly fighting to keep panels square and harder to stop at right tightness. Also I think theres to much panel movement from sunlight so if panels are screwed on the tops, the panels put more stress on screws... So this past August on my house addition I put screws on the low side of panels, easier to keep panel square and now the tops can expand and contract without putting extra stress on screws. Also my addition is fully boarded over so I put down weather-shield made for metal roofing since I'm concern with low pitch I have, roughly 14" drop in in 14ft..........
Think about water. Does it flow in a low spot or high spot? What will leak the most when that rubber washer degrades? Manufactures are in business to make money so they’ll tell you what makes them the most money.
It's got nothing to do with water in high spots and low spots -- that is a gross oversimplification that misses the actual problem. The issue is screw head movement when the panels expand/contract with temperature changes. Screws on the ribs experience greater movement and that causes numerous problems that contribute to leaks over time.
Phenomenal video! Thank you. I’m prepping for my metal roof now. Your video couldn’t have been better timed. Have a great day.
Best video so far!
Very helpful! Thank You for your time and for covering all the aspects I needed to gather materials , tools,, and plan the repair of my roof issues . I particularly appreciated you sharing the affects and having to plan for PSF of up-lift! Great video. Never unestimate the power of sharing knowledge and experiences . It is a raw form of caring about others! Thank You again!
Glad it was helpful!
Beginning carpenter here getting ready to do my first metal roof on a project. Thanks for all the detal and clear explanation!
Excellent job, good pace of explaining, clear speech, obviously a professional builder, just starting the meter portion of my build.
I love that wind/uplift loads diagram. Great video....thanks so much..................... Roy
Great video. Thank you. You’re brilliant
Great tutorial! Liked the use of type of drills. Todays clutches are a pain to use and adjust.
No they're not
Excellent and informative video. Thank-you once again Jack. Years ago I installed metal roofing on my garage and a wrap around verandah with the screws placed on the peaks but now I'm starting to see signs of moisture around the screws on the underside of verandah roof so I agree that the valleys would have been better. Also, on the verandah I was screwing the top half of the panel and my dad was securing the bottom half. He tended to apply a bit more screw pressure which would flatten out the peaks a bit more than mine, deforming the panels into a wedge shape. After 6 sheets it became quite apparent we were no longer running parallel and had to remove and redo the panels. Make it nice or do it twice. With time I suppose the rubber washers shrink and harden and with the expansion and contraction of the sheets, it creates more movement at the screws when they are placed on the peaks. The expansion and contraction would explain why the manufacturers only have one screw in the valleys, allowing the raised portions (peaks) to soak up the movement. Live and learn.
Sorry, this is becoming a long comment, but I have a question you may be able to help me with. We had local tornadoes this past spring and many farms and homes lost their roofs as well as downed trees. Luckily my roofs were ok. The original house has the ridge going in one direction and a later addition has the 2nd ridge going 90° to the first. So the wind was hitting a gable face on one portion while it rode the surface (like the airfoil you described) on the other. X and Z axis on your simulation model. I only noticed a day later, but the attic access panels for BOTH attics actually got sucked up into the two separate attics. Pretty scary to realize we may have just been on the edge of losing the roofs. So here's my question. Going back to the analogy of the roof becoming an airfoil, I'm not able to decide if the sucking in of the attic access panels was a good thing or not. I'm thinking it ended up increasing the pressure in the attic, thereby increasing the "lift". In other words, the access panels should maybe be secured down in some way, not simply dropped down into place. What is your thought, or if anyone else has insight into this, I would appreciate comments. Did the openings relieve a negative pressure or increase the pressure in the attics. Thanks again.
I should also mention the original portion of the house was built in 1910 and the addition around 1918. The soffits are closed with tongue and groove and not properly vented like todays construction. Plus on the 2nd floor, the rooms have slanted walls (the roof), again not providing proper air flow. I have vents at the gable ends to provide air circulation. This no doubt added to the negative pressure in the attics.
Wish I'd seen this fifty years ago when I was working on a pole barb building crew. Lots of leak repairs. Now I realize it was over-driven screws (or maybe it was nails back then) , not simply that they were driven into valleys.
Even now (until today), I've used wiggle wood and screwed through the peaks on Fiberglas deck roofings and the like.
Thank you, Jack, for making the rest of my life simpler.
Great video - thanks a lot.
The roof on the building which I bought is scratched in some places. Is there a way to protect the metal roof to extend its lifespan by for instance repainting it?
Any advice would be appreciated 🌹
Awesome video, my metal roof is 12/12 pitch, on SIP panels, very well insulated no heat lost what so ever. The biggest problem we get living here in Atlantic Canada is the winter freeze thaw cycles. The snow will not slide off the North side of the roof and when it thaws a bit and freezes again it forms around the head of the screw creating a solid sheet of ice on the roof, it’s impossible to get it off with any conventional tools. We have to wait untill spring and the melting cycle. Sometimes when the melt is slow there is an overhang at the edge where the ice slowly slides down getting 4ft or more of overhang before it brakes off with a thunderous crash. My suggestion to your viewers living in snow areas is to use the hidden screw type roofing, my neighbours went that route and have zero issues with ice hanging onto the screw heads.
Agree, standing seam roof, or the new style that mimics it with hidden clips/fasteners, is really ideal for areas with a lot of snow. Just be very careful with penetrations for vents, vent pipes, chimneys, etc, to make sure they have a proper diverter, skirt, and flashing, otherwise the sliding snow will tear things apart and cause leaks and damage. And there are certain parts of a roof where slides could be dangerous for what's below, so snow guards / stoppers might be needed to retain snow in those locations.
I know a few people that installed this type of roof and later had to go back and add diverters and snow guards to control what the snow does. Luckily they caught it early before significant damage happened. In bad situations, I've seen it peel open the roof and cause a major issue. A heavy snowpack has a lot of power when it starts sliding.
Luckily with a SIPS construction, you aren't going to lose any heat through the roof. That can be an additional concern in some climates, where you get additional freeze/thaw issues from heat rising through the roof. It's a hard balance to get right.
great info friend! answered every question i had! thx
Thanks for your advice
Excellent information! Thank you!
Thank you for a very helpful video!
There are now screws that have like an umbrella cap over the rubber washer protecting it even more from the elements.
I have used those -- they are great. I believe ZXL was the brand.
Screwing on the rib adds back tension to the rubber screw seal. However, if attaching to furring strips, most screw on the flat for strength of attachment.
My rule of thumb is, if you’re installing on solid decking, typically new construction or a complete roof rebuild, screw on the ridge. If you’re installing metal roofing on furring strips over an old roof, screw on the flat to get deeper penetration & additional rigidity of install on the roof.
I could be wrong.
Some do both the rib at overlap, & the flat everywhere else.
I spoke to a rep for one of the big metal manufacturers about 3 weeks ago and the conversation wandered to this topic. He said they advise against screwing on the ribs primarily because it deforms the panel profile and compromises sealing of the screw washers. The only panel in their product line that is suitable for screws on the ribs is 26ga PBR panel.
What an excellent informative video. I’m planing on doing our 24x24 detached garage. It’s 15 years old and the asphalt shingles starting to fail. Here in Ontario Canada, it seems that as per the manufacturer of local roofing steel, the ribs are the preferred location for the fasteners. I will be doing 1x4 strapping on top of the existing shingles for the new metal roof. I am debating what gauge of metal to use as I have the option of 29 or the heavier 26 gauge. I am also debating if I need to cut a ridge vent since this is an unheated detached garage with nice wide aluminum soffits. Since I have 2 x 4 blocking in between the roof trusses at the peak, cutting a ridge vent doesn’t seem to serve much purpose. I would like your thoughts on what gauge of metal I should use and if I need any vent at the ridge in your honest opinion, thank you
From the 12 minute mark where the dots are showing where to put the screws, what if you don't have that many studs going across in the middle to put the screws in? You would have to have 4 horizontal beams and yet only two vertical beams to make a grid support, not including the top and bottom support. I'm using boards underderneath. Maybe that's what was used. I am used to seeing grid supports. I know I am not using the correct carpentry terminology but I think you probably will understand. Thank you!
That roof has rafters every 2 feet and purlins every 2 feet, so it's a 2' x 2' grid basically. The number of fasteners and pattern specified by the roofing manufacturer is mainly setup for panel retention under wind uplift loads. Fewer fasteners means less uplift resistance. And that translates down through the framing as well. The screw loads holding the panel to the purlins must be handled by the purlin-rafter fasteners and the rafter-header fasteners along with any storm clips. And so on down to the posts and footings. Everything is connected and important. Skimp somewhere and the roof will have less uplift resistance and be more likely to peel off under wind loads.
Makes me wonder if slanted garnish at the gables would lessen uplift from blowing wind.
Or, would that affect water runoff?
I suspect there are shapes/modifications that could reduce uplift loads on roofs. However, it may be impossible to make it work for every possible wind direction coming towards a structure. You could likely optimize it for a certain onset wind direction though.
Hey thanks for the info. I've got a question for you. My house is about 30 years old and we are a couple kms from the coast with high winds. The colourbond is ok but the heads of the screws (12g 50mm) are quite corroded. My question is, should I replace the old screws with screws of a greater diameter or length? Also, are longer screws used for the ridge caps?
Normally the ridge cap does use longer screws if you need to reach into the framing below. But on some installs the ridge cap is only attached to the metal sheeting, with short self-tapping sheet metal screws. So you need to know how the original install was done to know what sort of screws are used at the ridge.
I have replaced screws on an older roof a few times and always use the same type and length screws, but of course the new screws were about 25-30 years newer and have better material for the gasket and a slightly different washer shape (to protect the gasket from the weather better). I would not deviate on screw diameter and length, but finding screws with a larger/better cap and gasket can only be an improvement.
Thank you Sir!
If expansion and contraction around screws causes them to unscrew, why don't installers drill a larger than 1/8 hole to allow a little movement?
I think the issue is that you can have 20+ screws on a typical size sheet, and it's the spread/distribution that really constrains the sheet.
Can you use self tapping screw to attach it to wood, 1x4 or 2x4 or plywood on the roof? It would be easier than predrilling at some places, also get cleaner and flat hole on the metal sheet, also easier to keep in place once starting to drill.. But would the screw hold any worse than regular screw in the wood/ plywood?
No, they don't have the right kind of threads, and won't have very good retention in the wood. Screw retention figures prominently into loads and uplift resistance and is very important for roof performance.
Great and informative video. Metal roofs get a bad rap because of poor installation. A properly installed metal roof should be the last roof you ever have to put on your house.
I had my metal roof installed I noticed that dust in getting in my attic is there anyway that can get repaired
Hard to say without knowing where it is coming in, but that is very unusual.
👍👍🇨🇦✌️🇨🇦✌️🇨🇦✌️ This is very good information 👍
Good video but, this would be great info video for me if you showed the exact metal roof and screws I used, like the metal roofing HD sells. HD sells several types but I bought mine from nearby lumber yard that sells the same as HD.....
All your charts showed perfectly flat tops or rounded, why didn't you show the common metal roofing HD sells, the top/peaks aren't perfectly flat nor are they rounded, theres a water channel on the tops with very slight curvature on the very top of the peak. It's a very common panel, there really no room for tape on the tops but calking could be used, which I thought of doing but didn't. Then the screws you showed, ALL have perfectly flat washers, never seen that type, the ones I bought have a dish shape washer that covers the gasket lot better...... Then why didn't talk about roof pitch needed for screw type metal roofing, I spent 10 hrs this past August looking online trying to fine answers to that, which I thought would only take 5 min.......
So on my shop that was built 10 years ago, I thought it was lot harder to screw panels that way, constantly fighting to keep panels square and harder to stop at right tightness. Also I think theres to much panel movement from sunlight so if panels are screwed on the tops, the panels put more stress on screws... So this past August on my house addition I put screws on the low side of panels, easier to keep panel square and now the tops can expand and contract without putting extra stress on screws. Also my addition is fully boarded over so I put down weather-shield made for metal roofing since I'm concern with low pitch I have, roughly 14" drop in in 14ft..........
Think about water. Does it flow in a low spot or high spot? What will leak the most when that rubber washer degrades?
Manufactures are in business to make money so they’ll tell you what makes them the most money.
It's got nothing to do with water in high spots and low spots -- that is a gross oversimplification that misses the actual problem. The issue is screw head movement when the panels expand/contract with temperature changes. Screws on the ribs experience greater movement and that causes numerous problems that contribute to leaks over time.
Putting a screw on a peak makes NO sence