Extending air-bricks

[markf]

Hi,

I am currently ion the process of building an extension and have two problems/queries:-

1. We excavated the footings and in one corner exposed a soil pipe running to a nearby manhole (we hoped we would just muss it). Will be OK to shutter the pipe from the footings with plywood, pack the pipe with pea-shingle and sand behind the ply, and alter the shape of the footing and hence wall running with the pipe such that it has a slight turn - or even bring the wall in completely by about 6 inches (yep thats all that is needed to clear the pipe from the concrete pour)? This would be the same as if the pipe had never been exposed by the digging, yes?

2. The side of the house has three air-bricks and naturally we need to duct these through the new extension subfloor (it will pass through the jab-lite), but what is the best type of ducting to use and what size?

Many thanks
Mark

 

[shaggy]

I'm not clear on the depth of the drain relative to the foundation. When the drain was laid the ground beneath it would have been disturbed so it's important that this doesn't affect the stability of the foundation.Have a look at this pic. Is this relevant.

 

[markf]

The footing trench is just over 1m depth from the finish level. The pipe passes through the corner of the footing at a depth some 800mm from the finish level. The damned annoying thing is that had the trench been 150mm shorter then the ipe would not have ben exposed and there would have been no problem

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The * above show where the pipe crosses the trench (the . are just to space things out so sorry for the mess it looks) and my proposal is to shutter the pipe and cut back the internal corner thus keeping the footing 600mm wide, at the expense of placing a slight turn on the rear wall so it can follow the footing.

I have since spoken to a building control inspector who agreed that should work. However the inspector coming out (today now) is not the one I spoke to. I just hope he is of the same opinion.

Any ideas should my 'solution' not satisfy the visiting inspector?

 

[shaggy]

It looks like my pic isn't relevant then as the drain is not lower than the foundation trench. I must say I would rather have the wall moved and keep the building square rather than have an angle on it.

 

[markf]

OK, building regs inspector passed the shuttering I put up so the concrete pour can now go ahead

Anyone have any comments regarding the ducting of the airbricks - do I just use 4" round pipe from each brick through the sub-floor, or do I need to use a different size/shape/system ?

thanks

 

[masona]

do I just use 4" round pipe from each brick through the sub-floor

That's what I did with mine and the building inspector was happy, I use 110mm orange/brown plastic underground pipe.