250mm footings or raft

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In this country I believe 450mm down is enough for frost
http://nhbccampaigns.co.uk/landingpages/techzone/previous_versions/2011/Part4/section4/sitework.htm

The most important thing is digging down enough to reach ground of suitable bearing capacity -thats almost aways going to be deeper than 450mm. You wont know until you dug your trench. The other thing to bear in mind is trees or hedges in the zone of influence.

I think if i go down 600mm itll be plenty. The ground looks good, see pics.
 
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The dpc in a garage wall performs the same function as the horizontal dpc in any other external wall, i.e. it is a barrier against rising damp.
NHBC Standards - External works - Garages , states a dpc should be provided at least 150mm above ground level ( which will usually be 2 course of bwk above slab level in a garage ) in garage walls. It also states that , depending on ground conditions , a dpm is not essential under a garage concrete floor slab, but if a dpm is not included the floor slab might show signs of dampness.
I cannot recall any architect, developer/builder, housebuilder or building contractor I have ever worked with not putting a dpc in garage walls or not putting a dpm under the floor slab for that matter.
 
The dpc in a garage wall performs the same function as the horizontal dpc in any other external wall, i.e. it is a barrier against rising damp.
NHBC Standards - External works - Garages , states a dpc should be provided at least 150mm above ground level ( which will usually be 2 course of bwk above slab level in a garage ) in garage walls. It also states that , depending on ground conditions , a dpm is not essential under a garage concrete floor slab, but if a dpm is not included the floor slab might show signs of dampness.
I cannot recall any architect, developer/builder, housebuilder or building contractor I have ever worked with not putting a dpc in garage walls or not putting a dpm under the floor slab for that matter.
But you and noseyall are not addressing the fundamental issue of why is a DPC placed in a wall that will be inherently damp anyway?

Whether it's driving rain or just atmospheric moisture, a solid wall is going to be damp, and it will release moisture to the internal space, and that is a fact. You can't get away from that.

DPC's were "invented" to keep habitable areas dry. People need to think more about what they are doing and why, and not just carry on robotically. It"s a garage it will get damp and it will get condensation.

And if you look that the image I posted, that's a typical detail on almost all new and past garages - designed by architects and under the NHBC .... and inspected by building control. Every single one with a band on brickwork below the DPC that allows damp on the inside. The DPC is there but pointless, but people put them in regardless.
 
The DPC is there but pointless
Not on a double or cavity wall garage it's not. Nor is it pointless on a single skin structure. Your argument for penetrating water via continuous driving rain is pants. My garage wall is (part) single skin and is bone dry all year round AND has a DPC/DPM.

People don't want puddles of water in their garage Woods - hence avoid garages built on rafts/slabs. Simple.

Note to self: Avoid any garage conversions regards garages built by Woody - too costly.
 
Every single one with a band on brickwork below the DPC that allows damp on the inside. The DPC is there but pointless
Massive difference between having damp compo in between a course or two of engineering bricks and nuisance puddles forming (EVERY TIME IT RAINS) on your garage floor Woods.

Deary me, you have gone all guns blazing on this one.
 
Not on a double or cavity wall garage it's not. Nor is it pointless on a single skin structure. Your argument for penetrating water via continuous driving rain is pants. My garage wall is (part) single skin and is bone dry all year round AND has a DPC/DPM.

People don't want puddles of water in their garage Woods - hence avoid garages built on rafts/slabs. Simple.

Note to self: Avoid any garage conversions regards garages built by Woody - too costly.



My garage will be a double skin of 4 inch block and i would not build a garage without dpc in it even if it was a single skin. There will be dpc going in the double skinned and heavy gauge under the slab either 1200 heavy guage or radon barrier.
 
'No dpc in wall leads to rising hydroscopic movement of soluble salts and lime and other contaminants up through the brick.'- quote.
Even if there are 2 courses of brickwork between floor level and horizontal dpc which are subject to rising damp and exposed to the inside of the garage in a single brick wall ,that is no reason to omit the dpc. Anybody noticed that efflorescence on the face of an external wall can stop at the dpc ,why is that ? !(see above quote )
ps My garage is single skin brick but is not damp on the inside due to driving rain.
The problem I had was the undercloak /roofing membrane/mortar bedding/mastic sealant verge detail letting water in.
 
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