We have to renovate an old house with masonry walls and no damp proof course.
One suggestion is to use a breathable dry lining material like CALSITHERM or PAVADENTRO
An alternaitve sugestion is to tank the ground floor with a product like a Water Proof Cement eg basementwaterproofingsite.co … c/detail/2 and then simply use normal drylining insulated plaster board over that.
I assume the latter would be cheaper and should allow the property to loose its moisture to the external walls without storing up problems later.
My concern with using the former products is that if water is transpiring into the room but blocked by a piece of furniture, surely this will be a hot bed for mould growth. Surely it would be better to tank the ground floor and dryline as normal?
What say you?
It really depends on how damp the walls are. If you have suspended timber ground floors then the walls are likely fairly dry (dry enough for Calsitherm of Pavadentro), but if your ground floors are not much above ground level then something like a layer of Hey’di K11 or that Sika one would be right.
One thing to remember about rising damp is that it can’t rise more than about 1.2m from the ground. This was the trick with the suspended timber floors in period houses. Any wet ground was more than 3-4ft below the floors so rising damp was rarely much of a problem. If you decide to tank the walls you don’t need to go any higher than about 5ft from the ground surface.
We have thick stone walls and we lowered the ground outside of the house to make sure the outside was lower than the internal floors and then put in suspended concrete floors with some insulation. The only place we tanked (?? with fibre glass) was under the shower trays.
The only downstairs area of damp we have now is where my OH remedied a subsidence problem with mass concrete (in hindsight he might have done things in that area differently) but it is also a north facing ground floor wetroom so it gets damp inside as well.