Saturated bricks below the DPC (2024)

Hi All,

I'm currently facing an issue with my house builder at the moment regarding the brick type that has been used below the DPC.

The majority of the bricks below the DPC are appearing saturated/wet which is causing them to look darker and develop algae on them.

On our development the builder has opted for using the facing bricks above and below the DPC on all the houses.

Looking at number of other housing developments in the area other builders have used an engineering brick below the DPC , which has much lower water absorption %.

The facing brick that has been used on our house has a 16% water absorption rating, hence why they are remaining saturated continually.

I've enquired with the brick manufacturer and the brick type has the correct durability rating of F2/S2, however they did advise that the high water absorption would effect the appearance used in the circ*mstances described.

Has anyone else experienced this issue ?

Any ideas how to tackle this ?

All of the bottom rows of bricks along the rear, sides and front of the property are affected.

The ground at the rear of the property is very wet and we are getting a landscape survey done.

I just can't understand why they did not use Engineering Bricks as that would have prevented this issue, plus it seems many other builders use them in these circ*mstances

this does happen a lot .....years ago only engineering bricks would have been used underground , but now a whole range of F and FL rated bricks and IN COMBINATION with special below ground mortar mix should be used below DPC

we can get samples of mortar tested and checked if you wish ...PM for details if you want more info

Hi,

Thanks for your offer of help.

I've just attempted to PM you and it's stated your not accepting PM's ?

This is our dpc level /air brick level completely buried. The NHBC have a techincal extra in relation to this in 2011 but it seems the building regulations are still being ignored. The external path is slightly above the internal floor level, so we have none of the 150mm requirement around one side of the house. This is not the most serious defect with out new home either! Why are the NHBC building control inspectors missing this when the CML the houses -so that then when the homeowner realises they have a problem, a mighty battle has to be fought - and how do they adjust the ground level afterwards to correct this.

OK ...in terms of NHBC and other WARRANTY COMPANIES ...the situation shown in your photo is classified as acceptable , i know because i have had arguments on site about this very situation

the NHBC terms that the loose stone allows percolation and helps to prevent splash back

the bricks if they are as the factory says suitable for underground but will stain ...are just that , and you should expect algae growth especially on wet elevations or elevations that dont get a lot of sun , such as between homes with the min 1m separation

the main thing is that the DPC is doing its job .....which it appears to be

''Ventilation
It is important that air bricks do not become obstructed.
By having the finished external ground level 150mm below dpc, air bricks are usually at least 75mm above the ground.
If the ground level is less than 150mm below dpc, air bricks can easily become blocked with debris and may
also allow water from adjacent ground to enter the building. This should not occur.''

The was eventually upheld after a fight and sending the NHBC their own technical standards and the building regs. The external ground is completely level with the internal floor, zero mm below , you can only just see the top of the AIR bricks they are fully obscured.

yes air bricks should not be obstructed , but you dont need to be too precious about it , for example if the grass grows a bit long

but your photo does

show an obstructed one , or one less than 150 below dpc , assuming dpc at level of the top of the vent

there should be a number of vents with spacing's as per manufacturers spec , but normally no less than 2m apart

the one shown in photo would meet requirements

sorry looking at wrong pictures , there was a single picture on earlier i was commenting on that

yours i take it then are the 3 pictures

in which case then , the picture clearly shows that the air brick is covered , and the path allows the rainwater to splash back over the DPC level causing lagea growth to brick work at higher levels

this is not an acceptable finish , it does not comply with building regulations or NHBC STANDARDS( unless its leading to the disabled access door ) the air brick should have a cut out around it , and the paving should be cut back away from wall and a perimeter of stone installed to allow water to percolate