Possible damp

[Stevie12]

Hi there I’m looking for some opinions on this deck I have installed in my back garden, has been build to provide a level surface from the patio door and the framing is fixed into the facing brick right up to the roughcasting, the framing seems to be about 10mm below the dpc height on the house but pretty tight up to the underside of the bell cast, and the decking board runs along the roughcast... I’m overthinking it a bit but do u guys think this will cause any kind of damp issues on my wall internal or external? Going to obviously be putting in a wider sill to span past the outer leaf but the image is just to show the height of the deck.. any opinions appreciated. Thank you 

[Russell griffiths]

Yep, the design of having outside finished height 150mm below the damp course has worked well for years, build above this height and your asking for agro. 

[Stevie12]

Yep you think it will be fine or yep u think it will cause damp? Are u saying it’s best to keep it 150mm below the dpc? Thank you for the reply Russel 

56 minutes ago, Russell griffiths said:

Yep, the design of having outside finished height 150mm below the damp course has worked well for years, build above this height and your asking for agro. 

 

[Onoff]

It will likely cause damp imo. I'd lose a foots width of deck and fill with something like Type 2 or flints etc and create a pseudo French drain.

[Russell griffiths]

Yep it will cause damp. 

Water bounces up when it hits the ground, it was found that I doesn’t bounce more than 150mm so building regs has been for a long time to have ground level 150mm below dpc. 

Lots of modern situations, disabled access and other fancy landscaping design have lifted outside heights up to dpc level, this is ok with newer designed stuff as you normally put other measures in place to mitigate the problem. 

 

With your place being older bringing the outside level up to dpc is asking for problems. 

[Stevie12]

Ahh I’m with you!! Thank you for the advice! One last thing to run by you... do u know what sort of damp and where it is likely to arise? Internal plaster? Roughcast? Thanks again

[Russell griffiths]

You will probably notice it on the internal reveals around that door, as this is a cold spot, you will also notice problems if you have poor guttering as more water pouring down able to bounce up.