What is rotten wood?

[JoceAndChris]

OK, I've kind of got the basics of the answer - black, soft, wet, spongy wood has got to be dug out and respliced, right? Oh, we're talking windows and sills, by the way.

But what I'm finding is dry, dessicated wood with millions of holes, some big, some small, and the tracks of worms. When you pick up a splinter of this wood part of it crumbles to a very fine powder, and yet the surface of it is hard and intact. I don't believe we have live woodworm or death watch in the house,this is the damage of an ancient infestation.

I could go on chiselling at this sill, but I'd have nothing left. What to do?

 

[biffvernon]

Eh-up, she's after our old friend Anobium punctatum now.

What you do depends on how much of the wood has been munched away. The timber is likely to be still fit for purpose despite historic infestation. Do nothing, or paint it over. Worse cases could perhaps be helped by a good soaking with a resin wood glue. Removing the affected wood and splicing in new bits is the last resort.

 

[JoceAndChris]

Biff - you're brilliant- thank you.

In that case I'll stop my destructive digging right away. The surface of the sill is hard, I've been sitting on it, but underneath this solid crust the wood has the texture of wholemeal flour. I think it was a bad case, but it's still been functioning as a sill. Resin wood glue sounds like a good solidifier, and then the splicing.

Thanks Biff.

xx

 

[AMc]

Sounds like you need "wet rot wood hardener" to me (from Ronseal), though I would want someone else to qualify if there are any period property pitfalls with this product. It's available at Screwfix (and many other places I'm sure) but they have the COSHH sheet online. That's what my carpenter and decorator have used to deal with bits of rot in my old sashes.

 

[JoceAndChris]

Though in the middle of splicing my window sill my father has decided to go to France for a month's holiday. (how could he?)

We've had a few differences of opinion about this, he was strongly in favour of removing the whole sill. His feeling is that the wood is very near the end of its life and needs to be replaced. My feeling is that if you applied that philosophy to the whole property you'd find yourself with a heap of rubble. Much of the wood here could easily be reduced to dust without too much effort. The stone that the cottage is made of is easy to crumble, and the lime plaster could happily come off on the inside with a few well aimed blows. Clearly gentleness and caution is called for.

What do people think about this wood? Should I have just left this sill alone in the first place? As it's the first (possibly the others are in the same condition) I'd really like to know if I've just created unnecessary work and removed historic fabric, or if I've done the right thing.

Also, those amongst you who recognise wood might concur that the original Georgian sill is oak, and the section (another old bit of the house; I recognise the paint scheme) which is going in when it's been tarted up some more is pine.

We had some words about that too.

Should I insist he scrap that bit and get me some oak?

 

[Andrew Bodenham]

That looks completely knackered and needs to be replaced with some new wood.

Preserving 'Historic fabric' is all very well - put the pieces of old wood in a glass case with an interpretation card for visitors to enjoy if you must, but pragmatically if the bits of a window frame are at the stage of coming off in your hand or going up the hoover then a workmanlike repair needs to be carried out. Which means cutting out the rotten / woodwormed bits and replicating them artfully with good materials to return the window to an 'as fitted' state so it will be good for another hundred years.

 

[JoceAndChris]

Very nice to hear from you again Andrew, particularly as you give me what I want to hear - that I needn't be carted off to SPAB's torture chambers just yet! :wink:

I am finding it tricky to know when to stop, I'm the kind of person that loves picking and poking and peeling, and Chris comes home and strops when he sees too much of the original fabric on the floor.

So your guide that if it comes off in the hand or gets vaccuumed up then repalce it is a good one.

 

[Lime]

So your guide that if it comes off in the hand or gets vaccuumed up then repalce it is a good one

My neighbour used to have the nicest original soft red brick front wall in the street.
Then he discovered the lime mortar could be scrapped out of the joints with a screwdriver.
By the end of the week he had demolished the wall.
He now has a very rough cemented wall (using the original bricks but all higgledy-piggledy) and it looks a mess.

I think he was a prat for doing it.

 

[JoceAndChris]

I couldn't agree more. Just becasue it can easily be scraped away doesn't mean it should be. What's hard for a beginner is knowing how much or how little to repair.

When you're used to modern materials (ie hard cement walls and plastic windows) it's a shock to live with crumbly friable laminating ones. It's especially hard when the people around you are strongly urging to replace it (as discussed in my thread on Others' Grand Designs)

I'll be leaving my lime mortar well alone.

 

[Andrew Bodenham]

Lime makes a valid point that one has to apply a bit of discrimination and common sense when assessing the condition of materials or components. Some things are easy to test; window sills should resist a good prod with a screwdriver - if the thing goes in then your suspicions of rot or insect damage are confirmed. What you are then dealing with is not historic fabric in need of conservation but materials which has failed in service and which requires replacement. I've seen too many bodged joinery repairs where rotten wood has had a bit of chemical treatment and has then been filled cosmetically and painted over. The material has no strength or weather resistance, soaks up water like a sponge and soon the problem has spread and become worse than it was before. Once the wood has degraded to that extent nothing you can do will put it right - it's like trying to make that old mouldering carrot in the bottom of the veg basket back into a firm, hard, snappable one - it can't be done and it needs to go in the compost. Ditto your window sill.

The problem comes with materials which degrade more subtly, like the brickwork pointing in Lime's example. Weathered material may be crumbly and easily removed, but may still be doing a fair job of protecting the mortar behind, and may do so for many years to come. Such cases need to be assessed carefully, and often making comparisons with similar materials on less exposed parts of the same building will give a useful indicator of the state of decay or otherwise. Ultimately you do need to develop an understanding about how the different elements of your building function, so that you can then make a judgement about the effectiveness with which materials and components are performing. Having come to your own decisions you can then carry out research to refine your understanding, so that you are well informed if you eventually decide to obtain advice from an 'expert'.

Alternatively you can just ask on PPUK. Much quicker and easier.

 

[JoceAndChris]

Ultimately you do need to develop an understanding about how the different elements of your building function, so that you can then make a judgement about the effectiveness with which materials and components are performing. Having come to your own decisions you can then carry out research to refine your understanding, so that you are well informed if you eventually decide to obtain advice from an 'expert'.

Alternatively you can just ask on PPUK. Much quicker and easier.

I was getting alarmed until I came to the last bit of that! Thanks for that very useful post Andrew: there are loads of bits of ancient wood here with Polyfiller stuffed unattractively in their holes, so it's useful to know about the good prod/screwdriver guideline- if all feels sound and good I'll just try to make the repair more attractive, somehow, but leave the surrounding wood intact.

What occasionally keeps me awake at night is the thought of all the wood I can't see. Others come on here posting about dry rot in hidden places- how do you find out short of taking the house apart? We can inspect inside our roof void fairly easily, but how about what's supporting the floorboards? Is it a case of if your foot doesn't go through the floor don't think about it?

Can you smell dry rot?

 

[yamin]

What occasionally keeps me awake at night is the thought of all the wood I can't see. Others come on here posting about dry rot in hidden places- how do you find out short of taking the house apart? We can inspect inside our roof void fairly easily, but how about what's supporting the floorboards? Is it a case of if your foot doesn't go through the floor don't think about it?

LOL! I see your problem, and for this reason I am in the 'try not to think about it' camp. Other than obvious problems like the window sill you've identified, how are you ever going to check every bit of the house? We have no access at all to the rear span of our roof void, and really we need to get a loft hatch in. This is low priority at the mo as its yet another cost, and its a case of if its giving no trouble then leave well alone. Always an element of risk of course, but if you can't take the house apart brick by brick (or rotting windowsill by rotting windowsill!) then there seems little point worrying about it, unless you have a definite indication to.

Of course, don't quote me if you find yourself sitting in a stately pile of rubble with nobbut a single span of bricks to call a building! :wink:

 

[Matt Green]

Others come on here posting about dry rot in hidden places- how do you find out short of taking the house apart?

Dry rot usually finds you.

It smells of mushrooms if the growth is or has been recent. Look where water occurs en masse in or near your house: around downpipes, drains, showers, washing machines, drains- that sort of thing. Really though, it's not much to worry about and I wouldn't waste time looking for it or losing sleep over where it might be.


M

 

[Lime]

I think dust mites much more of a worry when something "occasionally keeps me awake at night ".

 

[JoceAndChris]

Thanks for your kind reassurance Yamin, Matt and Lime. I'm hoping that the dust mites will have been poisoned by now with Nitromors and lead paint fumes. And I seem to have got rid of my fleas, which is great.

I'll try not to worry about dry rot, but there is a pungent mushroom smell in the wine cellar. There is also evidence there of old deathwatch beetle. Furthermore, the walls have a kind of blood-coloured mottling (a form of mould?) on the ancient lime plaster. The plaster there is so loose from the brickwork you only need to give a light poke and great chunks fall off.

Is it possible for dry rot to exist alongside efflorescence and damp?

 

[yamin]

Not to say that there isn't a problem with your cellar, but my parents have lived in an old vicarage with a smelly wine vellar since 1970. The cellar is a foot deep in water each winter (what a wonderful job it was going down for dads beer on a saturday, wellies and torch in hand!), and all three of the rooms down there smell really strongly. The only bad side of this that we have seen in those almost 40 years is that all the wine labels are lost to slugs! Just as well my dad keeps a book! And it was always great for growing mushrooms! And yes, mould growth everywhere. Ugh!

 

[JoceAndChris]

:lol:

I wonder how their wine fares in those conditions? Mouldy corks? If they're anything like me though, although the cellar is meant to be a place to store wine, precious little survives long enough to be able to tell if it likes a mouldy cellar or not!

 

[yamin]

The wine is delicious, even the stuff that manages to stay down there for a few years! There are some mouldy corks though, and this particular nesh daughter is NOT keen on the passing on of all this detail to guests at the dinner table, as it involves copious discussion of SLUGS while I'm eating. Ugh! :x

 

[JoceAndChris]

Mm, not guaranteed to put a smile on your guests' faces.

I've done some terrible things with insects though, and guests. (don't read this, Biff) I noticed that there were a few millipedes getting around in the room where I had the food all laid out. (we had a plague) The guests hadn't yet come in to eat, so I got out my whizzy insect vaccuum (have you seen those, they're amazing!) to suck them up. Unfortunately this little hand held vaccum has these little grooves in its handle. The millipedes were so skinny they got sucked right down into the innards of the machine. They then kind of sprayed out, all over the room and the food. I was frantically picking bits of millipede off the lasagne as they were walking in! No one noticed though.

 

[yamin]

:lol: :lol: :lol: :lol: Sorry, but I have remarkably little sentiment or care for anything smaller than a gerbil! Kill em all I say, but remind me to have white food if I come to your house for dinner!!!!