Can ACO eliminate the need for DPC being 150mm above ground level?

[Grsz]

Im in the process of buying a new build house, and it was unusual that the render goes all the way down to the pavement.

The builder said the DPC is at ground level, but it’s okay because the ACO drain won’t let the water reach the walls anyways, but I’m not sure how it will prevent rain splashing from the ground, making the walls wet. 
 

Apparently building control has already signed off on it, so it should be fine, but I want to make sure moisture from rain splash won’t make its way inside causing damp, so I was thinking putting a waterproof “skirting” to the affected area.

Edited March 28 by Grsz
Clarification on DPC level

[Moonshine]

The builder is not correct. The there should be a DPC 150mm above ground level due to splash (as you say).  i am surprised building control signed it off.

 

Is it block work walls?

 

This becomes an issue where there is a level threshold / ground. We actually put two in, one that was a cavity from the inside that went out to weep vents.

 

Then a second on the next block course (red below) where there was a break in the render with a drip bead.

 

 

I would also be interested why it looks like the render to the left at the base has come off in a small section (I can't see any weep vents?)

Edited March 28 by Moonshine

[Grsz]

34 minutes ago, Moonshine said:

The builder is not correct. The there should be a DPC 150mm above ground level due to splash (as you say).  i am surprised building control signed it off.

 

Is it block work walls?

 

This becomes an issue where there is a level threshold / ground. We actually put two in, one that was a cavity from the inside that went out to weep vents.

 

Then a second on the next block course (red below) where there was a break in the render with a drip bead.

 

 

I would also be interested why it looks like the render to the left at the base has come off in a small section (I can't see any weep vents?)

Thanks for your response.

 

Apart from staying away from this sale, what can I do to fix this, and how hard would it be? I’m not a builder, but it doesn’t seem like an easy DIY job.

 

Also if I leave it like this, and potentially putting a metal/plastic skirt there that will cover the splash, what’s the worst that can happen?

 

Should I ask building control to revisit (kind of a dck move, I know, but I’m not trying to make friends for hundreds of thousands)?

[joe90]

I agree, DPC 150mm up. I too installed two DPC,s like @Moonshine, parhaps water seal the bottom 300mm of render 🤷‍♂️

[nod]

That’s really poor 

 

[ProDave]

You shouldn't be buying a new house then thinking of ways to bodge a fix to the builders error.

 

I would tell them of your concerns and tell them you will buy it of they re do it properly but are not buying it like that.

[nod]

The render will soak up water like a sponge Then the frost will bring it off

 

[Temp]

My understanding..

 

DPC should be at 150mm.

I think only a limited number of renders are approved (by the manufacturer) for use below the DPC. 

 

 

[Grsz]

1 minute ago, Temp said:

My understanding..

 

DPC should be at 150mm.

I think only a limited number of renders are approved (by the manufacturer) for use below the DPC. 

 

 

That’s the thing, the render is not below DPC. It’s the DPC that’s at floor level.

[nod]

4 minutes ago, Grsz said:

That’s the thing, the render is not below DPC. It’s the DPC that’s at floor level.

It makes no difference The rain will hit the floor and continually bounce onto the render 

[saveasteading]

3 hours ago, Grsz said:

building control has already signed off on it, so it should be fine,

No, it just means that they haven't  spotted this gross error. There is an awful lot to look at in a short time. Plus when builders do something unusual it may not stand out. 

In this case the paving is too high so they have bodged in a drain.

But I don't think the bco can withdraw a certificate. You could phone and ask.

 

What's the worst you ask. The best is that the wet bit will go permanently green. The worst  is damp up the wall and into the house and the render falling off.

This is a walkaway or £20,000 discount matter. 

Any subsequent party may also spot this and the builder will end up reducing the price. And he maybe needs the cash now.

 

The solution is to lower the paving which will cost several £k and might not look ideal.

[Moonshine]

51 minutes ago, saveasteading said:

In this case the paving is too high so they have bodged in a drain.

 

And even with the drain, there is splash circa 150mm up the wall, and is evidence that the builder doesn't know why the DPC needs to be min 150mm or they are trying to gloss over the non compliant design.

 

53 minutes ago, saveasteading said:

This is a walkaway or £20,000 discount matter. 

Any subsequent party may also spot this and the builder will end up reducing the price. And he maybe needs the cash now.

 

tbh i don't think that many buyers would be eagle eyed / knowledgeable to spot this issue.

[joe90]

10 minutes ago, Moonshine said:

tbh i don't think that many buyers would be eagle eyed / knowledgeable to spot this issue.

I agree, it takes a buildhubber to spot these mistakes, it’s been signed off so no problem eh?.

[Grsz]

13 minutes ago, Moonshine said:

 

And even with the drain, there is splash circa 150mm up the wall, and is evidence that the builder doesn't know why the DPC needs to be min 150mm or they are trying to gloss over the non compliant design.

 

 

tbh i don't think that many buyers would be eagle eyed / knowledgeable to spot this issue.

To be honest, it was kind of weird that for such a low price no one bought it for 8 months, the price has been reduced over the course of it by more than 10%, while neighbouring new build has been sold in 2 months for 25% more. 
 

I thought I may have been just lucky to catch this one, but this may be the reason why they couldn’t sell it. Haven’t exchanged yet, so can pull out anytime, but we really wanted this house as it ticks almost all the boxes.

[Moonshine]

1 minute ago, Grsz said:

To be honest, it was kind of weird that for such a low price no one bought it for 8 months, the price has been reduced over the course of it by more than 10%, while neighbouring new build has been sold in 2 months for 25% more. 
 

I thought I may have been just lucky to catch this one, but this may be the reason why they couldn’t sell it. Haven’t exchanged yet, so can pull out anytime, but we really wanted this house as it ticks almost all the boxes.

 

If the neighbour property has been built by the same company does it have the same issue?

 

Also if this isn't right, what else may not be?

 

If you are still interested it may be worth getting in one of those professional snagger's in to take a look.

 

How desperate are they to sell? i am sure that you could look into how much remedials will be on the surveyors report and discount the price by that + PITA %.

[Grsz]

This is by a small developer building unique houses, so it’s not a big development. There is one next to this built by the same developer, couldn’t sell that one either. Attached picture of it.

 

There are two new builds by another developer in front of these build by a different developer that have been sold.

[Moonshine]

24 minutes ago, Grsz said:

There are two new builds by another developer in front of these build by a different developer that have been sold.

 

If they are a similar style and priced closely there may be a reason for that. 🤣

[Grsz]

Would it work if I take the top off the ACO drain, and fill it with gravel to have a “gravel trap”, and upvc strips around (got the idea from another post here with a similar problem), possibly making a skirt with waterproof tiles?

Edited March 28 by Grsz

[saveasteading]

1 hour ago, Grsz said:

take the top off the ACO drain, and fill it with gravel to have a “gravel trap”,

That was my detail on multiple industrial buildings where the external slab had to be kept high.

The gravel, being rounded, absorbs most of the drip impact and minimises splashes.  But it gets mucky and weedy and needs serious cleaning every couple of years.

you could insert a pipe along the bottom to carry the water away before it fills.

AND it would still be 100mm below the floor level as some splashing will continue, because gravel fill will hugely reduce capacity.

 

So for a big discount it is your shout, but be mindful that the issue remains in the long term for selling on.

 

It's a good point above about other people not spotting it. But most buyers need a mortgage and most building surveyors are (I like to think)  likely to spot that.

 

[Dave Jones]

the correct way of doing this is to put a cavity tray at ground level which 'lifts' the DPC 225 or however many blocks higher.

 

Builder cant have been upto much if they didnt know that.

[Grsz]

40 minutes ago, saveasteading said:

That was my detail on multiple industrial buildings where the external slab had to be kept high.

The gravel, being rounded, absorbs most of the drip impact and minimises splashes.  But it gets mucky and weedy and needs serious cleaning every couple of years.

you could insert a pipe along the bottom to carry the water away before it fills.

AND it would still be 100mm below the floor level as some splashing will continue, because gravel fill will hugely reduce capacity.

 

So for a big discount it is your shout, but be mindful that the issue remains in the long term for selling on.

 

It's a good point above about other people not spotting it. But most buyers need a mortgage and most building surveyors are (I like to think)  likely to spot that.

 

How about the tile skirting? With waterproof adhesive and grout it could create a sealed barrier to prevent rain from splashing onto the render.

 

its a shame though that both the warranty provider inspector, building control inspector, and mortgage valuer let this slip through. If buyers can’t rely on professionals, it’s basically gambling.