Danny Monaghan wrote:
Bookworm wrote:


Could you define what you mean by a 'membrane system'?

The probs with a bonded membrane is that a high water drive can disbond
the membrane from a weak substrate as is normally found in previously
damp brickwork. Once it is disbonded water builds up behind and
disaster results.

Look at cementitious waterproof coatings which will allow the substrate
to breathe. There are several on the market. I sell one but am not
going to advertise. Most can withstand about 20 metre head of water and
can be, and in fact must be, applied to a damp substrate. They are
applied by brush,roller or airless spray. They do not look very pretty
but can be overclad, (do not pierce the coating for batten fixings).

There are Epoxy/Bitumen coatings available but a) They do not breathe
and are OK for rearside applications (positive water pressure) and b)
Bitumen smell seems to last forever. Same rule applies regarding
fixings.


I was thinking about something like this from Newton Membranes:

http://www.newton-membranes.co.uk/System500.htm

Basically from what I've read, these systems that control water flow
rather than holding it back are better, and seem to be simple to install.

I am in the process of installing something very similar to the Newton
system in my basement. I've used Wykamol since the sales guy was happy
to sell to me as a non-qualified installer. They also sent an
installation instructions CD which was pretty clear. By far the biggest
problem is managing awkward shapes/corners etc. When it came to doing
the floor I built a small cardboard model of the floor and cut strips
of card to represent lengths of membrane and used this to work out all
the overlaps, cut and fold lines etc. When laying it with my general
constractor (no previous experience of the stuff) we used the model as
a template. Only cut 1 bit wrong out of 60sqm.

I used it in a refurb where I was putting in a new floor and rather
than use their perimeter drainage I installed perforated land-drains
(with geotextile wrapped round to prevent clogging) running to a sump.
Buy the sump pump separately as it's much cheaper and use something
like a small cold water tank as the sump chamber.

In total cost of the membrane stuff came to £750 and it's a pretty big
cellar, and an extra ~£150 for the sump pump and associated gubbins.

My cellar has rubble stone walls so the other problem was making
successful fixings. As a result I hung it like curtains as less fixings
required and will put up a stud wall inside this. If you've got brick
walls it would go up like a dream and you can either use a version
suitable for plastering directly onto, or fix battens to your 'plugs'
and dry-line.

This is definitely a DIY job and suitable for almost all types of
building (mines a listed Georgian townhouse). If you want further
specific advice email is as presented.

Fash