Treating crumbling old oak beams

[LadyArowana]

Probably no need for immediate panic. However, the situation needs to be assessed by someone who is properly qualified. Either a very good builder who is familiar with this type of building or a structural engineer likewise with the correct sort of experience. As you already realise the first step will be to remove the cosmetic boxing.

How long ago did you purchase? Were you given any of the information as regards the RSJ in writing or where representations to this effect given to your surveyor? Whilst the important thing to focus on is the structural integrity of the house, it may also be worth considering if you have a legal remedy against the sellers. IIRC when we bought there was a form with certain disclosures on, and if there is written evidence that they deliberately lied about what work they had done then there may be a case.

 

[fluffytail10]

Thank you so much for all your replies. I avidly read my SPAB handbook last night and have decided to remove boxing - how do i do that? and then see how wide the beam actually is. The boxing is about 30 cm wide so it may be that the beam is wider than it looks and the heartwood may still be intact. Fingers crossed.

The owners lied to us about numerous things - too many to mention. We thought it was odd that they refused to leave a forwarding address and now we know why :shock:

We bought the house in 2008 and i doubt there would be anything in writing, they were like eels when it came to pinning then down on anything. They renovated on a low budget which mean all the floorboards and doors had been removed and dumped in the garden - sadly all rotten by the time we turned up. Some of the boards were at least 30cm wide and had no woodworm so we don't know why they were removed. Sadly all our upstairs floors are now MDF boarding. Still we love 'housey' to bits and our trying our best to save him xx

 

[88v8]

An arrrrgh moment.

Sounds as if it has been visited by deathwatch beetle, of which there was discussion on here a wee while ago (translation - can't remember when).

Boxing might be plywood or hardboard or mdf I suppose. Poke at a corner of it to find a join, bang an old chisel in there and lever it apart. Be careful in the initial stage of poking and banging [Penners exclusion clause] in case there are pipes/cable inside the boxing.

You can post unlimited pics via Photobucket or Flicr - copy/paste the IMG code.

Ivor

 

[Penners]

I agree with what's been said above. Don't panic. Get the boxing removed, and this will enable you to carry out a more thorough examination of the condition of the beam.

To remove the boxing, first see if you can find the fixings that hold it together - nails or screws - and get them out. The soffit board (bottom horizontal board) corners will probably be fixed to the edges of two side boards, or to battens running along the inside of those corners.

If you absolutely cannot find or remove the fixing, then you'll probably have to resort to more radical techniques. Can you run a saw along either of the bottom corners to separate them, without damaging the beam? Remember that your sawblade may hit screws or nails so have a few spare blades to hand!

Once you've got the dismantling started, you may find that it becomes easier just to rip the boxing apart - particularly if it's nailed rather than screwed. However, resist the temptation to use a crowbar levered against the beam itself, as this would undoubtedly cause damage.

Once the boxing is off, you can use a long, thin blade to try and work out just how much good heart is left underneath the crumbling exterior of the beam. You can also ascertain the extent of the DWB infestation.

 

[fluffytail10]

sadly returns crowbar to toolshed....

I have managed to get the sides off but the underneath bit is more interesting.Firstly the original beam is covered in what looks like a thin coat of plaster which is mostly worn away. Along the sides are very old chunks of wood nailed which i think is when the beam was first boxed in. underneath appears to be remains of the original boxing a long plank going all the way across - this has about 5 layers of paint and wallpaper on it. Anyway, its getting the bottom off thats going to be a problem.

found of ton of beetle bodies and only one live one.... so far!

will try to link photos somehow

 

[FamilyWiggs]

The bottom may be screwed in or nailed on.... check for fixings under the paper/paint first.

And if you do need to use a crowbar or long handle to pry part of it loose, you can do this provided you are careful and lever against something other than the beam.

 

[Penners]

its getting the bottom off thats going to be a problem.

What a coincidence! That's exactly what Mrs P said when she started going to Weight Watchers.

 

[FamilyWiggs]

its getting the bottom off thats going to be a problem.

What a coincidence! That's exactly what Mrs P said when she started going to Weight Watchers.

Having survived the "best-bath-towels-on-new-lime-plaster" incident Penners, I have a spare tin hat if you need to borrow it. I suspect you may...

 

[Keithj]

found of ton of beetle bodies and only one live one.... so far!

Sounds like time to get the debeetlers in.

This sounds very like this house when we moved in. We came up with a simple guideline: any planks nailed on anywhere are to hide something that should have been fixed properly, and wasn't.

 

[Penners]

Penners, I have a spare tin hat if you need to borrow it. I suspect you may...

A kind thought, FW, but I suspect my protective equipment may need to be worn lower down.

 

[Matt Green]

Sounds like deathwatch, but do post photos nonetheless.

I think you need someone with a micro-drill like this:
http://www.sibtec.com/digitalmicroprobe.html

It would be good to know if that beam is hollow.

 

[Penners]

A digital microprobe sounds like something that could put proctologists out of business.

 

[tiddleyetom]

Cut out the affected areas about 6" back into the good wood and replace with new by jointing and pegging

 

[tiddleyetom]

Alternatively you could cut back beyond the rot and lap the joints- then bolt together. Depending on how much is gone (rotted away) go for the full replacement of a beam..

 

[fluffytail10]

Well my lovely beam is all uncovered and not as rotten as I thought. The bit I poked earlier was just a pile of dust rather than actual wood. It is about 30cm wide and has been chamfered into a kind of wedge shaped cross-section. It is a lovely silvery colour and in places has some limewash (?) residue. The nails removed were both 18th and early 19th century so I guess it was originally boxed in some time in the 1800s.

So what do we do with it now is the question? Do we fill all the beetle holes? leave them exposed? Is there a product that you can put on it that will stabilise it, as it is continually shedding dust - I have vacuumed it! Does it need oiling etc. I have no idea as I this is my first ever beam!

I am so excited by my discovery - have wanted beams ever since I can remember. I know it's only 1 but its a start

 

[livias]

Death watch beetle does not like central heating, so if your timber is in the middle of a centrally heated house then it is likely to have gone to sleep or dead or something. I am told that they make a loud mating knocking noise in spring. Have you ever heard it? Mind you I am not an expert. If you want proper advice then I can find you the name of someone who will do that, not someone who will try to sell you something. Let me know

As for your crumbly timber, if you are sure that it is structurally OK, then I suggest that you make up some limewater. Limewater is lime putty and water mixed together, just like limewash but thinner. Then it is left to stand for 24 hours until it becomes clear. Spray this limewater on to the timber, once a day for a couple of weeks or until you get bored. It is clear so will not change the colour of the timber, but you are soaking the timber surface with something that as it sets, becomes (very thin) limestone and the effect is to stabilise the wood. Caution! The limestone will also set in your sprayer and bung it up so wash out your sprayer each day when you have finished

 

[Penners]

Is there a product that you can put on it that will stabilise it

My daughter and I used a stabilising resin on an old oak window frame in her house, last year, and it did a brilliant job on wood that was just one stage away from talcum powder! I can't remember what was called, but I have emailed her to ask her. I'll post back.

 

[Penners]

Right, daughter has replied. The stabiliser we used was Bencon 20 Epoxy Consolidant, made by Benring Ltd.

http://www.benring.co.uk/our-products.html

It was approved by my daughter's CO, and did a really excellent job of stabilising and hardening some extremely friable oak members. Just be aware that it tends to darken the wood colour slightly.