Rising damp

[smilingcrow]

I have rising damp on the wall between mine and my neighbors house. What can I do about this?

[marden40]

are you talking about the party wall, and how old is the house?

[smilingcrow]

the wall that divides the 2 houses. the house is 100+ years old. I heard you can put sbr on it or something?

[marden40]

you really need a reputable surveyor to take a look.....Styrene Butadiene Copolymer (SBR) is an additive what's use in sand and cement renders etc....this is only part, not the solution to your problem.......... Party walls require remedial works in the same way as external walls. The insertion of a chemical damp proof course (DPC) is required and injecting a DPC is normally carried out in conjunction with the application of some sort of waterproof rendering ....... If you do not appoint a surveyor you will have no input in to how the work is carried out and any possible knock on affects to your neighbours property.......sorry if this sounds a bit heavy.

[marden40]

the first thing, if you haven't done so already is to determine exactly the root of the problem, that's why I suggest a surveyor....they will help you take the right course of action.

[The Builder]

A couple of things to think about Smiler. The additive is often used in conjunction with "tanking". That is, the plaster is removed, a barrier is applied to the wall, then plastered in the usual way. Tanking can be cement-based eg "Vandex", or it could be bituminous, such as "Synthaprufe", or "RIW".

Marden mentions injection, which is a method I've used a lot in the past. Basically, it's injecting a solvent based silicone barrier into the horizontal line where the dampcourse would normally be. Again, plaster is removed and then replaced.

Tanking can work well, but occasionally, being a barrier, it can "push" the damp along, or up, to another untreated area. It has to be well thought through.

Perversely, modern thinking is returning to traditional methods or damp control using lime plasters.
The thinking is that, rather than trying to stop the damp, the idea is to let it go. Plasters using NHL (natural hydraulic lime) are able to let moisture pass unhindered into the room (partly attracted by normal room heating.) That moisture can safely pass through the fabric of the building through normal ventilation.

Plenty to think about there. One point though........... don't let some "Damp Remedial Company send one of their "surveyors" along unless you are sure you'll get an unbiased opinion. They do tend to push their systems to the point of having you knock off plaster all over the place........... then charge quite a lot of money for a service you most likely don't need at all.

[The Builder]

^^^ methods OF damp control using lime................ sorry about the typo

[marden40]

good points there TB..........like you say, a few things to think about here and communication with next door is paramount...........I've been referee too many times where the quote is "it was ok until you started work" between neighbours.

[The Builder]

Oooh .............. that hits a nerve, Marden ;o) I vividly remember drilling and injecting into a party wall that turned out to be 4" thick ......... you know the rest ;o)

[marden40]

LOL........ I did the very same thing fitting a lintol............got a very sinking feeling when I knocked out the first brick....."and then there was light"..;)

[smilingcrow]

I already asked the neighbour and he has no pipes there or anything. So I am removing the old plaster tonight and a plasterer is coming friday to do the tanking method.
fingers crossed it will work