Woodworm - Crumbling Oak Beams

[meb97me]

Hi

We bought an old farm house just before xmas, on the initial survey it was thought that there maybe woodworm in the oak beams in the the loft conversion. A second survey was done by Timberwise but they said that there was no active infestation.

Great, so we thought!

Anyway doing a bit of DIY i bumped one of the beams and found it crumbled quite easily. A bit of poking with a knife has revealed that the areas where the previous bore holes were are extremely crumbly!! i've literally filled a couple of carrier bags with powder a chippings so far, but i'm a bit worrieed about going any further. The beams are fairly substantial but they are supporting a large roof.

The beams appear to have been coated in some sort of varnish which has given it a hard exterior but the crumbling areas you can literally pick apart with your fingers. You can pick down to solid wood so i was wondering what the best course of action was? remove all the crumbling wood, sand the beams and then treat again for wood worm?

heres a few pics

 

[GrahamPearce]

Hi

I live in a brick building attached to a barn it was mentioned in the 1841 census (so its at least 170 years old possibly much older), it also has plenty of oak beams much like yours.

In short, if the woodworm has been noted as dead, you have little to worry about, as for scraping around and removing the 'half eaten wood' its best to leave it.

We were given this advice by the county preservation officer, he also stated that the beams are much stronger than the appear to be, given that they were massively over engineered when constructed.

In short, if we wanted/must 'improve' the look of the beams and perhaps limit the dust fall, he said that gently applying bees wax would not cause any harm, but in general he still advised we should just leave well alone.

Anyway, if you continue to scrape away you will probably remove a lot of material in getting down to solid oak, but you will also be removing much of the character.

I have included a pic of one of my beams.

Untitled

• GrahamPearce
• 26 Mar 2013
• 1

 

[AronSearle]

Generally I would agree that it wouldn't be much to worry about, but the amount of damage is a more severe than usual, if the timber is still a load-bearing piece I would recommend getting it checked properly.

The reason I say "if" it is still load-bearing is I can see a piece of timber in one of the pictures that clearly used to be notched onto it, but is now no longer bearing onto it. It may be your piece of timber is now only acting to prevent spread, it will still be reasonably strong in stretch (or tension, not sure of the correct word), providing it still has a hard core.

Damage as shown can occur for a few reasons...

Sapwood in oak is prone to beetle attack for the first <20 years of it's life, after that the starch depletes and it is unattractive to insects, so often beams like this are peppered on the outside where sapwood was present.

When the timber gets wet it becomes attractive to insects, it is relatively rare for insects to attack dry heartwood, it may be the beam was exposed in the past leading to this damage. It's possible it has existing infestation, but I think it very unlikely.

You may also have had some old existing heart-rot damage in the beam, which is now only exposing itself as the outer layer has also "decayed".

 

[joe-90]

I doubt they are holding the roof up. My guess is that there is a modern rafter roof under the plasterboard.

Woodworm and fungal infection usually go together, my guess is you'll chop it away until there's nothing left.

Soak a load of polyester resin into it and forget it.

 

[AronSearle]

That's very iffy advice joe, the evidence supplied does not allow for the roof structure to be known.

The beam shown could be decorative or it could be there to prevent roof spread, there is no way of knowing from the pictures.