garage foundation.

[2019]

I thought id start its own thread on this query i have concerning strip foundations of a garage.

If the garage foundation will be a strip foundation 900 wide x 300 thick with 10mm wire mesh or rebar for a double skinned block walls with 100mm cavity, then later a 150mm slap poured with 10mm wired mesh for the floor area. This will be after the block footings have been built to dpc level.

When digging out for the strip foundation, is there any need for digging out under where the roller doors are going. Im assuming there isnt any need for concrete there, but im open for correction!

I have been considering adding another roller door on the side of the garage including the roller door on the gabled wall facing away from the house at my entrance. The garage openings will have a double steel beams or catnics for over the large openings for the doors.

 

[Ian H]

I’d have it myself, nice and strong where the car rolls in and out and another connection between the walls.

 

[2019]

I’d have it myself, nice and strong where the car rolls in and out and another connection between the walls.

This also crossed my mind but then id have to build up again with maybe block on flat for a strong base for the cars to drive over. At most, i think its 2.5 cubic meters of concrete and whatever block is needed.

 

[Ian H]

I converted my garage to a room and there was no foundation in between.

Just seemed a bit wrong to me for the sake of a bit of extra digging and concrete.

 

[2019]

I converted my garage to a room and there was no foundation in between.

Just seemed a bit wrong to me for the sake of a bit of extra digging and concrete.

If youve no foundation under one of your walls in the converted garage, whats holding the walls up?

 

[Notch7]

I thought id start its own thread on this query i have concerning strip foundations of a garage.

If the garage foundation will be a strip foundation 900 wide x 300 thick with 10mm wire mesh or rebar for a double skinned block walls with 100mm cavity, then later a 150mm slap poured with 10mm wired mesh for the floor area. This will be after the block footings have been built to dpc level.

When digging out for the strip foundation, is there any need for digging out under where the roller doors are going. Im assuming there isnt any need for concrete there, but im open for correction!

I have been considering adding another roller door on the side of the garage including the roller door on the gabled wall facing away from the house at my entrance. The garage openings will have a double steel beams or catnics for over the large openings for the doors.

900mm wide seems wide.

Wouldnt you just do a conventional trench footing? Typically 450mm or 600mm wide x 1M deep.

Depth of bottom of trench is entirely dependant on ground conditions, ie load bearing capacity of soil, shrinkability and any trees or hedges within zone of influence.

 

[2019]

900mm wide seems wide.

Wouldnt you just do a conventional trench footing? Typically 450mm or 600mm wide x 1M deep.

Depth of bottom of trench is entirely dependant on ground conditions, ie load bearing capacity of soil, shrinkability and any trees or hedges within zone of influence.

Its the regs here where i am unfortunately! The ground conditions are good. 900wide x300 thick in a 600mm trench min regs. If its a single skinned wall, it can be 300 wide. Here the regs are whatever thickness your block walls are, you multiply by 3. The cavity plus 2 100mm block is 300mm, multiply that by 3 equals 900mm. Notch7, i agree it can be excessive but thats the regs and i have to follow them. What im wanting to know, is there any need to continue the strip foundation under where the roller doors will be.

 

[Ian H]

If youve no foundation under one of your walls in the converted garage, whats holding the walls up?

I put one in before I built the wall.

 

[Notch7]

Its the regs here where i am unfortunately! The ground conditions are good. 900wide x300 thick in a 600mm trench min regs. If its a single skinned wall, it can be 300 wide. Here the regs are whatever thickness your block walls are, you multiply by 3. The cavity plus 2 100mm block is 300mm, multiply that by 3 equals 900mm. Notch7, i agree it can be excessive but thats the regs and i have to follow them. What im wanting to know, is there any need to continue the strip foundation under where the roller doors will be.

There probably isnt a need as such, but running the foundation across the door opening will certainly increase the strength a lot as there wont be any open ends. Any point load bearing on either side of the doors will be spread over a wider area of foundation.

 

[noseall]

There is no need for a foundation under the slab at the door detail. It could increase the risk of the slab cracking at this point. You are better off building a slab thickening toe at the point of impact, directly beneath the doors.

The trench only need be 600mm wide for a standard 300mm wide cavity wall.

 

[Leofric]

900 wide by 300mm thick reinforced concrete seems way of the top, 600 x 225m thick concrete are normal strip foundations for 300mm wide cavity walls here, but if your regs are different you have to work to them like you say.

 

[2019]

900 wide by 300mm thick reinforced concrete seems way of the top, 600 x 225m thick concrete are normal strip foundations for 300mm wide cavity walls here, but if your regs are different you have to work to them like you say.

I agree bt the regs here for min strip is 3 times the width of the walls. 300mm thickness aswell. It is excessive but the more concrete, the better the foundation!

 

[2019]

There probably isnt a need as such, but running the foundation across the door opening will certainly increase the strength a lot as there wont be any open ends. Any point load bearing on either side of the doors will be spread over a wider area of foundation.

There is no need for a foundation under the slab at the door detail. It could increase the risk of the slab cracking at this point. You are better off building a slab thickening toe at the point of impact, directly beneath the doors.

The trench only need be 600mm wide for a standard 300mm wide cavity wall.

One says better and the other says not better Im scratching my head now as to what one to choose!

When you say the slab cracking, is this the actual strip foundation or the actual 150mm floor slab once that is poured.

I googled slab thickening toe, i dont know what this is or ever heard of it.

 

[noseall]

slab thickening toe

 

[2019]

I was thinking maybe this is what it was. This is how raft foundations are poured.