Should I rebuild this stop chamfer in plaster? (with pics)

[inwood]

I have a beam which has lovely stop chamfers at the four corners. However as you can see from the photos below one of the corners has suffered significantly from rot and insect attack.

I'm proposing to rebuild the stop chamfer in lime plaster (also filling some other rotten areas with the same) and then limewash the beam.

Anyone any experience with plastering a beam? advice?

Stop chamfer in good condition:

What no stop chamfer??:

 

[chuckey]

Looking at the surface of the beam, it looks as though the surface is loose and friable. I doubt if plaster will a, stick to it, and b, stay there for very long.
Presuming that the core of the beam is still solid, the aim is to make a job out of it. I would totally clad it in 6mm ply, glued and pinned, then fill in the missing chamfer stop with filler, sand the chamfers all over to suit original. Then paint it. It will look fantastic, it won't drop bits of plaster dust on you and the surface won't get so mucky so quickly.
Frank

 

[skier-hughes]

I'm cleaning mine up the best I can and then leaving them as they end up.

 

[Andrew Bodenham]

Plaster is not really the right material for this job. Not only will you have difficulty getting it to stick to the friable surface, but the edges, even when chamfered, will always be prone to mechanical damage. Differential expansion and humidity changes will soon have the plaster falling off again.

Faced with a very similar problem in my own house I decided to clad the beam with planed redwood planks. These were screwed on to the existing beam and the screw holes plugged. Stop chamfers were then run on with a router. Several coats of paint later the "beam" looks fine. A relatively quick and easy solution. Using real wood rather than ply or MDF gives a more 'realistic' surface finish due to grain, knots etc.

 

[shelli]

we are also just wrassing (sp?) off our beams and seeing what we end up with - beams the thickness of curtain poles probably - I kid you not!

bl**dy woodworm :x

 

[Gareth Hughes]

we are also just wrassing (sp?) off our beams and seeing what we end up with - beams the thickness of curtain poles probably - I kid you not!

bl**dy woodworm :x

If you mean defrassing, can I rapidly draw your attention to SPAB infor sheet 2 before you whittle your beams away to nothing:

http://www.spab.org.uk/html/online-shop/the-bookshop/?sSubCategory=Information%20Sheets

Information Sheet 2 ‘Timber Treatment - A warning about the defrassing of timbers’ explains in a cautionary manner the advantages and more often the irreversible disadvantages of removing surface timber that has been degraded by beetle attack.

 

[shelli]

I actually WAS kidding Gareth - the remaining beams aren't quite that bad - but the ones we have had to replace were crumbly right through - and we were hoping to reuse them elsewhere in the house by cleaning them up - It was a bit of a shock when the builders lobbed one of the (old) purlins out of the roof and it broke in 2 when it landed. :shock:

And thanks - everyone around me here has been calling cleaning up old beams by removing the surface layer wrassing - I shall tell them that unless they're using a fish to do it they're wrong :wink:

unless 'tis a quaint northern term

and thanks for guidance notes

 

[Penners]

Inwood - could you not set a new piece of oak into the worm-eaten face of the the beam, and then cut a new stopped chamfer into that?

 

[inwood]

Penners, I like your idea. It hadn't even occured to me that I could joint in a new piece of timber to recreate the failed end - despite the fact I recently spent two weeks scarf jointing two French doors that by the end seemed to have more new wood in them than original timber :wink:

Not sure the beam is oak but I'll have a root around in it and try to work out what it is.

As to plaster sticking to the beam - other beams in the house have been plastered and quite well it would appear - they seem to be holding on to the plaster quite well.

 

[Nemesis]

Many a historic beam is strengthened with a metal plate or two also...