Fitting new Laths

[skier-hughes]

I have my new riven Oak laths.
They are supplied in all the same lengths, so will need cutting down.

How do I fit them?

Some of the old ones are virtually horizontal, whereas some are at a near 30' or so angle. Of course these may well have slipped down!!

Should they be horizontal?

How do I fit them then? Cut to a tight fit and bend and snap them in place? They will be about 10" in length, so not much for a bend in a piece of wood 9mm thick. How do I bend and snap if there is plaster behind? I could remove plaster, but I'd rather like to keep as much of the old as possible

Do I fit the laths as they are, or do I coat them with linseed oil first?

Lime plaster will be going on in the end.

Graham

 

[fjpdesigns]

Don't coat them with anything , but make sure they are well wetted before you apply the plaster otherwise the dry wood will suck out the moisture and dry the plaster before it has chance to carbonate.
I cut mine to slightly shorter than required, giving room for movement.
I pre- drill before nailing as the laths have a tendency to split and use either galvanised or stainless steel clouts [ the smaller headed type about 25 mm ] .
Keep them as horizontal as possible with a gap of around 10mm between them. If you have some attached already under the existing plaster I wouldn't try to move them too much or you may end up cracking or loosening the old plaster.

 

[skier-hughes]

I appear to have been not clear enough.... re your nailing suggestion.

My laths are to fit into grooves in two uprights, between which will be lime plaster. see pictures here
http://www.myvideoproblems.com/testfiles/personal/kitchen/26-09-07_1710.jpg
So no drilling and screwing, or should there be?
None of the others in place are?????

Graham

 

[fjpdesigns]

Sorry Graham, I misunderstood. They are indeed rather short for bending and snapping into place. If they won't go, could you fix thin pieces of oak, about 20mm wide to each upright, then you could fix the laths to those. I can't tell from the photo what the thickness of plaster is so don't know if you'd have enough depth.[there doesn't seem to be much of a gap between the old laths.]
Anyway, they should still be horizontal with enough gap between and behind for the plaster to squeeze through and form keys.
Another quick thought; 9mm sounds very thick for a lath for that area. if they wont bend sufficiently perhaps you could try thinner laths or you could try cutting each lath in two down its length [ the wider side]. They be much more flexible then. They will still be strong enough to hold the plaster, especially if you mix plenty of hair or straw into the first coat.
Joe

 

[middi]

The most frequent used method to locate wattles between "studs" was(is) by locating two, three or more staves ( stout horizontals forced into purpose cut out depression between the upright studs) then tying the required wattles perpendicular against the staves with malleable willow branches. Daub would have been applied to this, usually by hand

There are numerous examples of slight variations to the above. As building methods evolved split laths were used and nailed horizontally against rhe upright studs with hand made nails then "trowel" rendered. Eventually machine cut laths then plasterboard.

The biggest difference between " staves and wattles" and " lath and plaster" is that with the latter the beams( studs) would not have been exposed, as "good quality" oak became scarce(r), in some instances total cr*p, it would have been very convenient to cover them up with laths and rendering them.

If you wish to plaster the "laths" and do not show beams then nail them horizontally in position, unless you have wrough iron hans made nails, stainless steel (is best) or galvanised fixings have to do.

 

[skier-hughes]

Studs will be shown, plater will be between them.
Laths were 9mm to match what was already in situ.
Here's some more pictures, hopefully they'll show it in more detail.

 

[worms]

Naive question... Would the plaster not adhere well enough to the infill that is showing between/behind the studs in the picture even without the laths?

 

[skier-hughes]

No, it's very loose and what would stop it from just falling out in one big piece.
This part used to be a detached house from the main building, so this was once an outside wall.

 

[Flyfisher]

Fair point about the loose infill but, conversely, might the infill prevent the new plaster from 'expanding' behind the laths to give a good grip?

(Is there a particular word or term for the bits of plaster that protrude through and 'grip' the laths?)

 

[FamilyWiggs]

"Nibs" I believe.

 

[chuckey]

It would seem to me that the original laths would be swivelled into the slot. Have you tried steaming your wood?, this is the way boat builders bend their wood. It basically softened it, though in your case once you have manipulated your spongy bit of wood into its slot, you will have to lean something on it to hold it straight while it cools.
frank

 

[middi]

To insert new or existing ( staves) laths between the oak studs is very simple, just tap upwards the slightly higher than orizontal section to remove it, reverse the process to insert it back, The staves are cut slightly longer with oblique ends so that they could be jammed between the studs( the reason why the do not appear to be horizontal it is because, depending on slightly longer lenth, some tend to jam at slightly diffferent angle to the horizontal.

 

[skier-hughes]

New laths fitted, now a few things just to finish off before getting the plasterers in.

 

[FamilyWiggs]

Nice job Graham, I think. Pics a wee bit small...

 

[skier-hughes]

I know, was going to upload direct from phone and it auto shrinks them. I'll take some more.

 

[JoceAndChris]

Very interesting and looks fab- I also like the way it's taken you ten months to get round to it. A realistic time frame - no, on second thoughts, I'd have taken 3 x as long!

 

[skier-hughes]

Planning is the most important part of any job!!!!!!

 

[worms]

In the end how did you decide to fit the laths?

 

[skier-hughes]

I decided to give the job to someone else!!

We cut them to size, trimmed a little of an angle on one end, put flat end in place and hammered gently other end so they were horizontal.

 

[skier-hughes]

Edited and better pictures are in my original post.