New build house air bricks covered!?


5 Mar 2008
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United Kingdom
I've just moved into a new build house and there is a very small patio outside the back door with a drainage channel seperating the slabs from the house. The patio is completely level with the back door cill, i.e no step and therefore is the same level as the ground floor. I've been told this is for disabled access so a wheel chair can be pushed in easily. The back door also has a flat threshold. This is all ok except that some of the air bricks that are spaced along the back wall are covered half way up by the drainage channel due to the high level of the patio. I think they are the 'stepped' type air bricks for the suspended ground floor. Is this acceptable? As its a new build I thought a building regs officer would have had to seen the house and sign it off. I want to extend the patio across the back of the house but this would mean blocking the other air bricks half way up aswell. Surely this cant be right?! I think my only option would be to take up the old patio and relay a new one at a lower level.

My other concern is that my back garden which consists of mainly clay slopes down towards the house and every time it rains i'm worried that the drainage channel isnt going to cope and i'm going to see water coming in my back door!

Any help/advise would be greatly appreciated
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Ah the wonders of spec-build housing...where no one really cares, other than making money. If the site agent is crap, then so will the quality of the houses be.

Modern houses have to have one level entry door, for disabled access requirements, so that is the arrangement that you have and hence the height of the patio.

As often happens, someone hasn't thought it through fully, hence party covering of your air bricks which ventilate the underfloor void. Should have been picked up by the BCO as they won't sign the completion certificate until disabled access is complete; should also have been noted on the valuation survey, if you've got a mortgage.

It requires attention. I note that it's new-build, are the developers still building on the estate? If so, go and see the site agent and get them to sort it. As an alternative, you should have NHBC or other 10yr cover on the property, so get in contact with them, if you get no joy with the builder.

As for the garden, if you're experiencing water run-off onto the patio, install a french drain before the patio parallel with the back of the house, spade width x 300 or 450mm deep, line with a geotextile membrane such as Terram or Filtram, fill with pea shingle, turn the membrane back over the top and put the topsoil back.
Thanks shytalkz thats just as I suspected. I should have known as we have had so many problems with the house its unbelievable. The buliders just keep sending out sub contractors to sort the problems. The worst thing so far has been in the attic, the felt covering underneath the false chimney was overlapped in the wrong direction which resulted in a wet landing ceiling and ruined carpets when it rained. I argued that, that amount of water shouldnt be coming into contact with the felt (it was as if there were no tiles on the roof, the water just poured in when it rained) but was told by the sub contractor who came round not to worry as all the houses in our row had leaked. :rolleyes: Amazingly he 'fixed' it by spending about 30 seconds in the attic. I asked if it would leak again, he said lets wait and see. :eek:

I'll talk to the builders about the air bricks but i think i will have to insist that some one with authority comes to have a look. I suspect that all the houses in our row have been done the same so they may say dont worry about it!

What do you think they will do to put it right? As i'm going to be laying a patio the full width of the house I may as well just do it myself. Would I be 'allowed' to put a step in so that I can lower the patio. I dont really want to put a ramp in.

Thanks again.
Unfortunately, these kind of faults are far too prevalent, despite the supposed controls that are in place. The site agent is obviously a hopeless numpty.

It would be interesting to see just how he "fixed" it. You are right to be suspicious...

Can you post a pic of the back, might be able to give you some better idea of what could be done. Point to note is that, if they come and do it, you will have to have the spakky entrance arrangement. Technically, you shouldn't undo it, even if you do it yourself and it just might be the kind of thing that gets picked up by a valuer, in the (likely?!) event you sell up.

If you get no joy getting them to sort it, go to NHBC and they will lean on them; for the first two years, the builder has to sort out warranty claims.
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As we are on the subject i also have a new house with void, but i have no vents what so ever :eek: I have been told that i don't need them as the base of the void is cemented? is this right? as if it were damp in there the open joist above for the kitchen and dining room would be effected?

Sorry to hi jack but similar question :)

All underfloor voids must be vented, concrete solum slab or not. How that would have been missed in BCO/NHBC inspections is anyone's guess.

You sure that you haven't got a suspended reinforced concrete slab? If so, that doesn't mean there's a void, it's cast over a sub-base, but with reinforcement in it, enabling it to span between walls and not rely on the ground for support. This arrangement isn't vented.
Thanks Shytalkz, yes absolutely sure it's a void, i have been down there! - basically we had a dip in the kitchen floor and they cut a hole out to inspect the joists, so i had a good look around, took pics etc, as i want to in the future have door from the back integral garage wall into the void for extra storage.

You have got me worried now, as there is no vents at all, neither on the 2 other identical town houses next to us.

Should i contact the NHBC?
Bit more than a normal void then, you on a sloping site perchance? Either way, should be vented, if you've got NHBC, go to them.
Yes sloping site, back garden level with second floor, so the kitchen and dining room which are at the back of the second floor facing the rear garden have a void below them.

I have the NHBC, so will contact them on the weekend

Just got this from a mate who has just qualified with HIPs

Ok according to building regs guidance part C 4.13b:- any timber suspended floor next to the ground should: have a ventilated air space between the ground covering and the timber.

Been here over 16 months now! Just think in 5 years time i could walk into the kitchen and fall through :eek:
Just got this from a mate who has just qualified with HIPs
Despite his "qualification" :LOL: , that is the correct part of the ADs. Also C4.14a and b and diagram 6 for a sloping site. BS Code of Practice 102:1973 Protection of Buildings Against Water From the Ground gives an alternative approach. Don't have a copy of that, so no idea what it involves, but I'm betting that ventilation still features in there somewhere...!
LoL, I call him the new tax inspector :)

But he must have learnt something as he was the one that point this out in the first place!! LoL

I have let the Customer Care team know about this and we'll will see, if no joy i'll go direct to NHBC.

I expect the answer will come back - "Sir, your particular type of void does require ventilation"

If i get stuck after the NHBC, who do i see next?
If i get stuck after the NHBC, who do i see next?
You won't: NHBC Standards Chap 5.2 D22c is quite specific on ventilating voids under suspended timber floors. 10 year Ted should get a slap for not picking this up on his inspections.
LoL, I call him the new tax inspector :)

But he must have learnt something as he was the one that point this out in the first place!! LoL
He might have learnt something, but does he understand why.... :LOL:
Yes, he understands :LOL:

So who will get the wrap for this Barratts or the NHBC inspector?

This may work min my favour as i want to get into the void from the garage, as it's the best way to gain access, i'll have them do an entrance etc :)

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