Rotten floor boards - dry rot vs wet rot?!

jkgray

We have recently discovered that a number of the floorboards in our (little used) dining room are rotten.

I have just stuck a screwdriver through them and the pictures - follow link: http://1drv.ms/1GWIdPX - show the result. :eek:

We bought the house - C15th grade II listed - about 18 months ago. I know that in the dining room there had been a leak from some boxed in pipework prior to us buying it. This was repaired by the developer vendor during the buying process.

If relevant, the survey when we bought the house told us that the original floorboards had been lifted, a concrete sub floor laid and the original boards laid over the top.

Does it look like the boards affected by wet rot or dry rot from the pictures?

If wet rot is it as simple as taking up all affected sections and replacing with fresh timber?

If it's dry rot do I need a specialist?

Any other comments / advice?

Thanks :beer:

daveyjp

The white cotton wool looking substance is dry rot. You may will need a specialist as it will travel to all damp timber and it needs tracing to its full extent.

Doozergirl

Yes, It's dry rot.

It doesn't 'jump' to items like some people think, because it needs water, but it will follow the path of water, more than likely back to its source so you need to strip back to make sure. It's gotten behind plaster on projects we've owned.

27col

Definitely dry rot. I will never forget what it looks like after my tussle with it in my first house in 1961. I seem to remember taking a blowtorch to the brickwork after all the wood had been removed.

AlexMac

https://www.spab.org.uk/advice/technical-qas/technical-qa-26-timberdecaying-fungi/

brightontraveller

Dry rot (*which your's is ) a fungus that will have a white or yellow appearance on the wood, whereas "wet rot" is just natural wood decay answer to both really is remove source of water and reduce the moisture content other wise replacing etc it will always come back? Doing it yourself or firm the major difference is the peace of paper that says warranty .

If you choose to do it yourself then look at the combinations of Borax, (also known as sodium borate, sodium tetraborate, or disodium tetraborate) and antifreeze (ethylene glycol) without the colour will kill most rots and other things. Some also use these to try and eliminate or slow down the process i.e. preservation without instant removal not sure I would but plenty do… If you remove then remember to treat the newly cut wood ends etc and the wood end of newly exposed in existing timber so many don’t...

Many will bleach burn adjoining masonry as well any debris/ spores etc are best removed with as little disturbance as possible e. g hovering them up every time you re use the Hoover your blowing them everywhere, light mist and throughway or exclusive use dust pan and brush often best way

mustangu

looks like dry rot, worth getting a dry rot survey done by a specialist. Some are free and also give you a quote for the work. untreated the dry rot could spread through walls and render the house worthless.

teneighty

Whilst the photos certainly look like dry rot I would not necessarily jump to that conclusion. There are plenty of species of wet rot that look very similar and I have had cases where I was convinced it was dry rot and sent samples away for laboratory analysis and it comes back as a wet rot species.

The important thing at this stage is to remove all that decayed timber and examine the immediate area, floor, walls etc. to see if there is an ongoing problem with dampness. Until you are sure the area is dry it really doesn't matter what sort of rot it is as it will just come back and spread.

For example did the previous developer allow the floor to dry out properly after fixing the leak before they put the floor back down? Is there an effective damp proof membrane under the concrete floor slab? Casting a new concrete slab in an old period property can cause problems so it has to be done properly to avoid it causing damp issues.

You probably need to get some specialist independent advice.