Geogrid needs to go deep into the soil. Not just a foot or two. The filter fabric should be going between grid layers, not continuous top to bottom. Retaining walls fail with the soil shearing at an angle from the base. That grid does not go past the failure plane, so if it wants to topple, it's just taking the grid with it without any resistance. Roughly, the grid should go back as deep as the wall is tall. The right way is to have an engineer design it. Shouldn't add more than about $600. That's cheap insurance.
@@jamieshotter9762 That's excessive on tall walls. Allanblock says typically around 60% of wall height, but a geotechnical engineer should make the call.
Please take an NCMA class guys. This wall is not correct. That is woven geotextile fabric NOT filter fabric. Even filter fabric should not be used as you are using it. It will not allow water to drain and should never be draped as you have it. It is only used on the top to keep soil out of #57 stone. This wall is over 4' and requires engineering. No engineer designed this. Geo grid minimum length ever to be used is 4' and that is not 4' long. This wall is also supporting those scary steps and the porch and its doubtful that was taken into account. That foundation should have mortar pushed in there and not expanding foam where rodents and water can just pass through. Its frustrating that someone needs to be a certified plumber to connect a sewer line, but anyone can do a retaining wall where children can walk next to and have no training whatsoever.
Well said, first thing I noticed was the Geogrid is nowhere near deep enough to add any support and using that “filter” fabric is the biggest sin that wall will blow out 10x faster than if it just hadn’t been used
@@davekushman2363 Techo Bloc recommends a proper filter fabric. Are you saying the engineers and national engineer standards are incorrect that they go by? They have guides on their website for reference. Dirt migrating into the gravel is a real issue between hydrostatic pressure and maybe freeze thaw heave due to the dirt holding water. This is what I used after my research: SRW EC8 Non-Woven 8oz Drainage and Filtration Fabric It's punched layers of polypropylene that let water pass through.
Geogrid cost you more than the Home Depot wall block you used and that’s not even the biggest issue, hope you pick up the phone when they call you back
Suggest using drain tile at the bottom of your crushed stone for water to have somewhere to go. Thanks..
Geogrid needs to go deep into the soil. Not just a foot or two. The filter fabric should be going between grid layers, not continuous top to bottom. Retaining walls fail with the soil shearing at an angle from the base. That grid does not go past the failure plane, so if it wants to topple, it's just taking the grid with it without any resistance. Roughly, the grid should go back as deep as the wall is tall. The right way is to have an engineer design it. Shouldn't add more than about $600. That's cheap insurance.
geogrid should go back twice the distance as the wall is tall
@@jamieshotter9762 That's excessive on tall walls. Allanblock says typically around 60% of wall height, but a geotechnical engineer should make the call.
@ryanmcgowan3061 I'm a civil engineer. My two times comes from the angle of friction of typical soils, 25 to 35 degrees
@@jamieshotter9762 Gotcha. I'm about to sit for the PE as well.
If the depth of his grid is what he installed, it will be fine. Not over built, but enough to last 20 years. Those are very heavy blocks too.
Short retainer wall on a slope
Please take an NCMA class guys. This wall is not correct. That is woven geotextile fabric NOT filter fabric. Even filter fabric should not be used as you are using it. It will not allow water to drain and should never be draped as you have it. It is only used on the top to keep soil out of #57 stone.
This wall is over 4' and requires engineering. No engineer designed this.
Geo grid minimum length ever to be used is 4' and that is not 4' long. This wall is also supporting those scary steps and the porch and its doubtful that was taken into account.
That foundation should have mortar pushed in there and not expanding foam where rodents and water can just pass through.
Its frustrating that someone needs to be a certified plumber to connect a sewer line, but anyone can do a retaining wall where children can walk next to and have no training whatsoever.
Well said, first thing I noticed was the Geogrid is nowhere near deep enough to add any support and using that “filter” fabric is the biggest sin that wall will blow out 10x faster than if it just hadn’t been used
@@davekushman2363 Techo Bloc recommends a proper filter fabric. Are you saying the engineers and national engineer standards are incorrect that they go by? They have guides on their website for reference. Dirt migrating into the gravel is a real issue between hydrostatic pressure and maybe freeze thaw heave due to the dirt holding water.
This is what I used after my research: SRW EC8 Non-Woven 8oz Drainage and Filtration Fabric
It's punched layers of polypropylene that let water pass through.
Geogrid cost you more than the Home Depot wall block you used and that’s not even the biggest issue, hope you pick up the phone when they call you back
It was a rebuild with their existing retaining wall block. I agree the block was junk but it's what the client wanted
This will fail also
I feel its not enough grid for that load, he cant do much however with the current site conditions.
That is some pissy block, why even bother with grid 😂
Geo grid systems are slow and labour intensive. Useless in todays world.