Summary: basement waterproofing
and cellar conversion.
Damp walls are very prone
to Condensation and Black Spot Mould. If the walls are made of a single
brick or block 'skin', or have no cavity, or are below the damp proof
course, or partially below ground, or 'earth retaining', they will always
be cold. Traditionally the way around this problem was to cover up with
wooden paneling, but this tends to rot. So, 'dry lining' was invented
and from this has evolved the 'Air Gap' or 'Cavity Drain' Membrane,
a dimpled, plastic sheet which, because of the dimples, allows air to
freely circulate. This prevents moisture from being trapped (as in conventional
'tanking') which can drive dampness sideways and upwards.
Lining Walls - choice
The three main methods are;
1. Board on battens - directly
nailed or screwed to brickwork, stone, block or render - likely to decay
on old, damp salty masonry, and at risk from Dry and Wet rots unless
efficiently treated and ventilated.
2. Inner walls - block walls
built inside the building, with an air gap or insulation. Often used
in Barn Conversions, where wall thickness and lost internal space is
not an issue. Not a vapour barrier, so damp and 'salts' from the unventilated
cavity can eventually reach the inner wall decorations.
3. Air gap membranes - a
modern, vapour proof barrier lining - it is a dimpled plastic sheet
fixed onto brick, stone, block or render with plastic plugs to form
an air gap cavity. These Membranes can have a plain surface, for battening,
or a Mesh surface for direct plastering or plaster boarding. Ideal for
cold, single leaf walls and for lining rooms with cold solid walls.
Air Gap Membranes - how
1. Remove all gypsum plaster
(solid sand and cement render can stay), wooden plugs and bonding timbers.
2. Check whether you have
any 'active' water weeping from the wall, or if the area has ever suffered
from flooding. If there has been any activity you will need to install
a drainage method - either a traditional drain or a sump and pump. (Ring
for help on 01626 331351).
3. Choose your wall finishing
method - battens and nailed plaster board (with or without insulation
between the battens) or direct plastering with Bonding Plaster, or Plaster
Board on adhesive 'dabs'.
4. Battens and nailed plaster
board - use Kontract Membrane
- the plug heads have pre-formed holes ready for No.10 or No. 12 self
tapping screws, to fix the battens.
5. Plastering or Plaster
board dab fixed - Mesh Membrane
- the welded-on mesh supports the plaster or the adhesive.
6. The floor may also need
to be covered with Kontract Membrane - a 'floating' (not screwed, nail
or glued down) tongued and grooved chipboard or concrete screeded floor
(3 inch/75mm thick) can then be laid. Where liquid water is involved
this floor Membrane has to be joined to the wall Membrane - this is
called the 'sealed system' and must incorporate a drain or a sump and
pump. Floor insulation can also be inserted.
Neutraliser - a clear liquid used to neutralise 'salts' in render,
plaster or masonry, either in an attempt to save otherwise sound plaster
or as a preparation prior to re-plastering to our Specification. Apply
two coats, wetting in between with fresh water.
Membrane - easy to install dimpled plastic 'air gap' dry lining
membrane, supplied in rolls like wallpaper. Designed to cover damp or
salty walls and provide a fresh surface for replastering with a modern
lightweight plaster (usually 'bonding').
A new, easy to install, cream
damp proofing product - no pump required, no mess, no smell - includes
injection nozzle extension. Designed to gently diffuse into the wall
to form a water repellent layer - a 'damp proof course' (DPC). It is
approved by the British Board of Agrèment - BBA Test Certificate
No: 02/3961 - as used by the professionals. The BBA is a Government
Approved organisation which has been testing building materials for
over 30 years.
If you need any help with
lining damp walls or 'tanking' products, Property Repair Systems staff
will be pleased to give you completely free, no obligation advice on
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and insect attack
- how to treat penetrating dampness in walls and plaster
- how to treat patio decks and yacht decks
- how to kill Dry Rot in buildings
- epoxy resins for repairing wood, concrete, brick and stone
- upgrade doors to 30 minutes fire resistance
- how to quickly repair joists and beams of any size
- our Home Site
- treat steel with Intumescent Paint to provide fire protection
- systems of repair, with step by step methods
- how to repair timber beams
- how to kill and prevent woodworm and death watch beetle
- all your questions and our answers about woodworm treatment DIY