wood in walls

[charlie-ia]

our walls are rubble stone with lime. they are filled with odd bits of wood, some obviously old versions of rawlplugs, some seem just a bit random. all are usually very rotted. are we right removing them all as we find them? (we put a suitable stone in instead).

also, all the bedroom joists are resting on a strip of 2" x 1" wood (i will call it a wall plate unless there's a better word) this has also rotted. it runs most of the length of the house, but only down one wall. we have to replace this as the joists are nolonger properly supported.
it would be possible to put a thicker piece of wood in, maybe 3"X2" or more. would that be a good idea?

should we use wood preserver? i would have thought so, but i have read what you lot think about spraying for woodworm willy-nilly and wondered if wood preserver was just as pointless.

should we re-plaster over it using lime, or leave as much as possible exposed? it did have plaster over originally, but has rotted. the external wall is rendered with old cement, so i don't think it can breathe properly. perhaps just a thin layer of lime wash would be better?

 

[Andrew Bodenham]

Our house also has lumps of wood in the stonework. Those cowboy builders 100 years ago just stuffed in whatever came to hand so they could finish the job and go home early. We have removed the wood and replaced with stone where we have encountered it.

For your joist packing I suggest replacing the wood with shims of slate, or brick if you can fit it in. These would give a more durable bearing for the joists. If you incorporate a layer of DPC material it will keep the joist ends from getting damp and possibly starting rot. I'd probably slosh some preservative around on the joist ends if they have been in contact or near wood affected by wet rot. Others get twitchy about using chemical weapons, but brush applied in small areas shouldn't be a problem.

 

[Matt Green]

Are the joist oak or pine (makes a bit of difference in regard to recommendations)?

Also: have you checked the joist ends to see if they are sound? Give the bearings a firm prod with a stout screwdiver on both sides, if the plate has decayed the joist bearings may well have suffered too.

Matt

 

[charlie-ia]

The ends of the joists are a bit rotted, but not to scarey. perhaps 5 ends will need replacement or some strenghtening.

is slate the best idea? i thought the wood was there to distribute the weight of the beams?

any recomendations for wood preserver that doesnt stink, but still does the job?

 

[Penners]

The bits of wood in your walls could be several things. Small bits are probably, as you suggest, plugs for wall fixings. Longer pieces may be "grounds" for a dado, picture rail or other wall fixings. Some may just be junk, as Andrew says.

I can't see any reason why you can't replace them with stone. It's probably a good idea if they serve no further purpose.

As regards the wall plate, Matt's question is certainly important. Personally I would try to replace the plate like-for-like (and deal with the rotted joist ends similarly). I'm not a fan of brittle materials like brick or slate for this job - they don't have the resilience and flexibility of wood, meaning that they can crack if there's any movement.

If your plate is softwood and you replace it with same, you could use pressure-treated, if you're concerned about future rot.

 

[Cloudscape]

Another couple of ways wood might be found in stone walls seems to have occurred in part of my house. I found the partial remains of a skinny lintel and a cill, where a small hatch previously existed in a stone wall, but has long since been filled in. Also, where a stone-walled 'extension' was added to the existing stone structure, two or three horizontal pieces of wood (2-3 feet long) seem to have been used as wall ties. Nothing fancy - just added in at odd angles.

 

[Matt Green]

is slate the best idea? i thought the wood was there to distribute the weight of the beams?

Maybe, or maybe to level the wall up ensure the floor is halfway straight. the damage doesn't sound too terrible, I'd go along with Penners and replace like for like using pressure treated softwood or oak heartwood.

Slate is OK, but is better used closer to the ground where water rises up rather than falls down (easier to isolate the timber).


Matt

 

[inwood]

also, all the bedroom joists are resting on a strip of 2" x 1" wood

Do I understand this correctly? You have a piece of timber 2"x1" fixed to the wall onto which all the joists for that wall rest? If I do understand correctly you're joists are supported by only a 1" bearing. I'm no structural engineer but that doesn't sound great.

Hopefully I've misunderstood. Do the ends of the joists actually penetrate the wall?

 

[charlie-ia]

all the joists go in to the wall. the 1"x2" piece of wood just runs in a channel where the joists rest in the wall. there is plenty of stone to hold the joists. it looks like its more to cushion the joists or provide a level surface, than to hold the floor up. even though this bit of wood has rotted, the upstairs floor doesnt move much. the joists look/feel mostly ok.
the way the wooden batten was put in, with a couple of layers of fairly small flat stones either side, it would be easy to replace with larger sturdier piece of wood, without too much difficulty. would there be any benefit? does this bit of wood have a better name?

 

[Penners]

Charlie, is there any chance you could post a picture? It would make the situation much clearer.