John Kelly wrote:
Phil L wrote:
John Kelly wrote:
My extension was built and I'm about to start laying topsoil and grass
and generally finishing off. I'm a little unsure of how high I can go
with the topsoil. Obviously I can't go above the damp proof course and
that's too high up anyway but I'd like to go about 2 bricks below it
as that's what it is around the rest of the house. However there are
gaps between some of the bricks that low down - it's about 5 bricks
between gaps. Can I go up past this level or are the gaps there to
let air in?

150mm down from DPC is the maximum you can go to with your soil/turf
(or about 2 bricks with joints)
The holes are weep holes and are there to allow moisture to drain out
of the cavity....you can go up to the weep holes but I wouldn't cover
them if I were you - the amount of moisture they will deal with in a
year would probably not even fill a bucket, but if left standing in
the base of the cavity, it will cause lots of other problems,
especially when it freezes.

That changes things then. I'm not a fan of it but if I were to put
gravel down between the grass and the wall would that be alright? That
might give enough drainage.

I would personally risk that, yes.

Having seen what a good gravel filled trench that has some way of
draining, itself, can do in terms of getting rid of water flung of
gutterless thatched rooves, .another even BETTER option would be to
excavate enough to put in a plastic perforated pipe, in gravel, and
arrange for that to drain somewhere lower down.