Rising damp on party wall in semi-det Victorian house

Me again, Thinking of buying a Victorian semi - haven't seen the struct survey yet but says there is indications of rising damp in the party wall. Presumably this requires a new DPC - easy enough in MY side, but what about the neighbour's? If a new dpc is laid on only one side will it be as effective? How do you determine which side is causing the problem, and again what if it's the neighbour's side? Thanks in advance - again! R

Reply to
Richard
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If a wall needs damproofing, then it's the whole wall and can't be divided in to my side your side in this case. if it's damp on your side, then I'm sure it will be damp on theirs to.

If it is a cavity wall, then it may need the roof doing rather than the floor area. If rain is getting in at the top, then it may be manifesting itself as damp at the bottom of the wall.

To be sure, you really need to call in the guys who know what and where look for the causes.

Reply to
BigWallop

I think that you need more information before jumping to conclusions.

From my own experiences and those of friends concerning properties of this age, "rising damp" tends to be more of a label given by surveyors and others to cover a multitude of damp wall conditions.

It is fairly rare that there is dampness on party walls away from the exterior walls, so I would ask the surveyor to be more explicit about the exact location.

It's also fairly rare for moisture to soak up through the brickwork, the DPC having failed. In properties of this age, the DPC was usually slate.

What is far more common is that the ground level outside has become built up over the years with the addition of soil or perhaps concrete and the DPC has been bridged. If it's by a couple of courses of brick there can be a fair amount of water penetration through the brickwork.

Another common issue is faulty guttering or downpipes leading to water running down the wall when it rains. If you consider that in semidetached properties that there is often a rainwater downpipe at the boundary taking water from the main roof and perhaps bay windows, then a failure will result in dampness at the party wall as well.

These points should be checked before embarking on more draconian treatment. What often happens is that a damp company comes along and does an injection DPC and while doing so lowers the ground outside perhaps to open up air bricks. The damp problem is cured, but could have been done just by lowering the ground.

You would also need to know about the construction of the party wall - whether it is single or double brick thickness.

Ask the surveyor - that's what you are paying for. If he just recommends calling in damp proofing company XYZ, check at Companies House to see if he or his wife is a director. Then also get several quotes and see whether the recommended treatment varies.

.andy

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Reply to
Andy Hall

Not so. It can be fairly common.

When I bought my old cottage, it had been injected on the exteriors walls, and *some* of the interior walls as far as could be done..BUT in one case an interior wll containged a huge chimney stack, and wjhen we finally demoilished teh house, that while area (raised wood floors) teurned out to have essentially a pond underneath it. Massive amounts of water would soak upo through teh bricks of the hearth into the walls.

It was the expense of underpeinning and DP'ing that stack that was the reason for a drastic rebuild as much as anything..that and the discovery of massive rot in the structural timbers due to rising damp, as well.

If the house does not have solid floors, the potental for underfloor water and dampness is huge. Ok you CAN help by digging a french drain around it to lower the local water table, and control with central heating, and myabe an underfloor sump and pump, but rising damp on internal walls is a big problem.

Injection will fix it, if there is space below the floor boards. And no huge chminey/hearth in it. Your neighbour should share costs. Laying solid concrete floors over DPM is also indicated.

Or non existent.

Unlikely inside the house - this is NOT an external wall is it?

Possible.

Reply to
The Natural Philosopher

Be sure it is really damp. Surveyor's reports usually include the dampness in the walls line. Frequently it is a bit like the Soviet era aviation meteorology reports which always without fail said there was a 10% probability of thunderstorms, even when the weather was excellent. No-one wanted to get sent to a gulag if a freak storm hit.

If the plaster, paint and any wallpaper stays on the wall, I wouldn't worry myself. If they are peeling, blown (or recently replaced), there may be a problem. The damp readings were probably taken with a Heath Robinson resistance meter that measures how hard you push more than the dampness.

Christian.

Reply to
Christian McArdle

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