Dry rot or Wet rot

[Angelica]

There seem to be a couple of similar topics in the forum but nothing that gives me a conslusive answer.

We bought an 1870's house stone built and there was definately rot in the a back room that had the outside road onto the back wall and no DPC. The skirting was rotten along a back and side wall, a couple of floor joist ends were rotten and a complete indoor window sill had crumbled. We had 3 companies come out 2 said wet root 1 said dry rot. All said a DPC was required.

We went with the middle priced quote to do the DPC which was one of the firms that said it was a wet rot issue, they assured us that it was wet rot caused by condensation and the fact that house had been closed up and not lived in for 8 years. They sorted the joists, and the DPC. (The window sill is still to be replaced by a local joiner shortly.)

We received guarentees for the work and all seemed fine.....but I am such a worrier I now am nervous what if it was dry rot? I have read more and more what a problem it can be if not sorted.

Does anyone have any advise, thoughts on the topic? How can we get conclusive advise when different firms say it is different types of rot?

 

[Softus]

Dry rot is rare, but is renowned for being terrifying only because it can grow undetected for long enough to cause structural damage.

It seems rather unlikely that your window sill was the victim of dry rot - you would see a trail of fungus leading to the rotten wood.

Best bet is to ensure that all the parts of the house that need ventilation are getting it, and that all parts that need to be heated are getting it. Then replace the rotten bits, then test for continuing evidence of damp.

If you can get under the floor and into the loft space, then it would do you no harm to treat the timbers with a proprietary fungicide.

Adding a DPC to a wall that had never had one is unlikely to be a huge benefit, or indeed any benefit at all. For example, if the damp is coming through the floor, or between the floor and the wall, then a DPC in the wall will achieve nothing. Equally, if there's any way for water to regularly wet the outside of the outside wall, then it may be able to get through to the inside.

 

[Nige F]

Now Angelica will worry that money`s been spent for possibly no result Ask the joiner to have a look while he`s replacing the cill- he should give a correct answer to the rot question and probably the amount of underfloor ventilation required.

 

[Softus]

Now Angelica will worry that money`s been spent for possibly no result

Well, don't shoot the messenger, but that's how it is I'm afraid. Injecting a DPC into a wall, with no other remedial work and with no DPC in the floor, will achieve absolutely nothing. This is why every competent damp-proofing company always finds other problems when they start work - what they're actually doing is finding the real problem and addressing it at the same time. Incompetent dp companies won't even find the other problems, or will attempt, and fail, to fix them.

Ask the joiner to have a look while he`s replacing the cill- he should give a correct answer to the rot question and probably the amount of underfloor ventilation required.

Sorry to disagree Nige, but there's no reason why a joiner (unless more than just a joiner) will know about underfloor ventilation - better to ask the local Building Control Officer for advice, or a competent builder. There are regulations for under-floor ventilation, and it might even be that there are airbricks that have become blocked - it happens.

 

[sidecar_jon]

Rot of all kinds seems to be down to ventilation. While ordinary home owners are told always to rip eveything out the advice that lage stately home owners get is diferent, they are susualy advised to increase ventilation. And replace whats not structualy safe anymore. id stop worrying, new wood is going to last some times even if its "dry rot"... i know of one thames barge yacht thats been riddled with dry rot for the last 30 years and its still floating. (no kidding , i scooped out parts of the galley with my hands, it was that rotten!)