Attic Timbers treatment?

[jungle_jim01]

Hi, I've just started pulling down the old lathe and plaster in ceiling in the attic which was in a bit of a state...messy job! The timbers all look ok but i'm thinking that before i start putting in insulation and new ceiling it's probably worth treating. Has anyone got any recommendations? Thanks

 

[citizensmith]

If you are rich - Cuprinol 5 star
If you are less rich I have used some very similar stuff made by Blackfriars, I am not sure if you can still get it but it was 1/2 the price.

When we had our roof done the builders sprayed timbers with some stuff that they had to dilute from a liquid concentrate in a yellow sachet - I am having a pint with him tomorrow - i'll ask what its called.

Low tech - Paintbrush it on generously
High Tech - garden sprayer

In either case - mask and gloves and cover up, these things are meant to kill beasties and prevent beasties starting up home and we humans also count as organic beasties.

 

[Feltwell]

Has anyone got any recommendations? Thanks

Yes - don't. You say the timbers are in good condition, they've been like that for over 100 years I presume, so why do you want to spend money and spread nasty toxic chemicals round your house?

If it's not broke then don't fix it. The effectiveness of timber treatments is very dubious - loads and loads of posts on here if you search - generally if the timbers are dry then you won't have a problem.

Save yourself time, money and speading nasty chemicals round your house and don't bother!

 

[biffvernon]

Oh deary deary me.

First, lathes are for wood turning; you mean lath, without the 'e'.

Second, STOP. Don't destroy the historic fabric of lath and plaster. It can be repaired.

Third, don't use poisonous chemicals. Ensure the timber is dry, then it won't rot or get eaten.

There's a fourth but I'm too polite.

 

[middi]

Hi

It is not clear in your post why you need to treat the timbers.

I presume you have noticed some signs of woodworm which has alarmed you. Before you start splashing chemicals about ( especially with a spray gun!!!) you should consider if it is absolutely necessary. I many cases this is not necessary and definetely NOT necessary as a precutionary measure.
If the timbers in question are oak it may have little or no effect unless it is professionally assessed and carried out and in most instances it is not effective or necessary.
If the construction timbers in question are softwood and there is signs of active woodworm then it may justify using chemicals for treatment.

Middi

 

[FamilyWiggs]

Has anyone got any recommendations? Thanks

As above. Stop and don't spray around pointless but nasty chemicals.

 

[citizensmith]

I should have asked if you have/will have full access to inspect attic timbers at any time. If so then above comments have value as you can deal with a timber issue if it arises. Rot happens because something much more fundamental is wrong. On the other hand my roof access is highly impractical and inaccessable so i chose to know it had been done when there was an opportunity do do it.

 

[Lime]

I have yet to find any form of wood treatment that prevents rot when the circumstances arise that allow rot to occur, except one.
The Romans used it for posts that went into the ground.
They charred the surface of the wood.
Charcoal does not rot.
Other than that treatment I know none that work for any length of time worth speaking of.

Even GPO telegraph poles and railway sleepers rot and the old variety were pressure impregnated with heated pitch.
What possible hope has a scant chemical spray got for protecting roof timbers?

Nil points.

 

[Penners]

There's a fourth but I'm too polite.

:lol: :lol: :lol:

A New Year's resolution, there, Biff?

:wink:

 

[jungle_jim01]

Thanks for everyone's replies. I appreciate the concern for my lack of conservation on this one, but regrettably finances mean i'm compromising here. On pulling the plaster off i've found that at least half is plasterboard anyway, but no insulation behind..brrr! Most timbers are ok...dry and good nick and look like they always have been. The are a couple however which have suffered from a leaky roof (which is now fixed). I think they'll be ok once dried out but was wondering about treating for protection against rot in the future?
Thanks again...apologies to Biff for the mis-spelling of 'Lath'

 

[Matt Green]

I think they'll be ok once dried out but was wondering about treating for protection against rot in the future?

Whatever you apply will leach out when the timbers get wet. Because rot needs water and whatever you apply will likely be water based. You would be better served spending the money on an inspection hatch and checking for leaks occasionally.

M

 

[Penners]

apologies to Biff for the mis-spelling of 'Lath'

No no! Don't apologise, JJ! It's an old running bit of pedantry on this forum, and we always love dragging it out of its dusty box once again!

 

[Flyfisher]

I have yet to find any form of wood treatment that prevents rot when the circumstances arise that allow rot to occur, except one.
The Romans used it for posts that went into the ground.
They charred the surface of the wood.
Charcoal does not rot.
Other than that treatment I know none that work for any length of time worth speaking of.

I've read about charring fence posts, but always in conjunction with tarring them as well, to prevent any moisture getting through pores and holes in the charcoal. I can't remember where I've read this, but found this article that describes some old methods for preserving wood including - rather astoundingly - 'painting' or soaking in petrol. :shock:

I can understand the stated rationale for this (to replace the water-based sap constituents within the wood) but I don't think I'd give it a try on my roof timbers, or any other timber in the house. In fact, I'm not even sure about the wisdom of the technique for fence posts!

 

[AMc]

I think they'll be ok once dried out but was wondering about treating for protection against rot in the future?

If the roof timbers get wet and stay wet they will rot eventually - the trick is to stop them getting wet to begin with and make sure any rain blown under the tiles or condensed underneath the tiles can evaporate out naturally.

You would be better advised to spend the time and money making sure the upper surface is in good condition to prevent leaks and make sure that there is ventilation between the insulation between the rafters and the tiles so that air can move and deal with natural condensation by venting at the edges.

Our lath had been stripped of plaster before we bought the house. As we had to insulate and reroof and funds weren't limitless then we took it all down.
The builders insisted on spraying an anti fungal/insecticide on the roof timbers and at a weak moment I gave in. I hope for their sake that the chemicals don't last for 25 years as they took very little precaution in spraying them but they were at least working from above. I wouldn't do it again.

We have a 'non breathing' room with a low partially vaulted ceiling as we had to insulate the walls and ceiling and there simply wasn't room for a foot of rockwool/sheepswool all around so lath and lime plaster weren't really an option and I went for modern alternatives.

We used isotherm (similar to kingspan or celotex) over and between the rafters to create a 'warm' roof. The gaps above were aluminium taped to form a nearly perfect seal and the gaps below were sealed with expanding foam to create another more or less airtight seal. Then plasterboard was screwed to the rafters which was skimmed. That basically eliminated the chance of warm moist air getting into the timbers from below. Doing the job again I would use insulation backed plasterboard for the ceiling (we used this for the walls anyway).

Up above the roof was battened along the rafters to leave an air gap, breathable roof felt draped over the top and stapled to the battens leaving a gap and then cross battened for the tiles to be hung. So there is a layer of insulation between the rafters, full sheets over the rafters, battern and felt the a gap and the tiled surface.

I hope that helps a bit. If your ceiling is flat then your insulation options are simpler and you should definitely fit a loft hatch if you can, even if you can only poke your head through with a torch to take a look now and then. I'd buy a prebuilt unit so you get a good seal and insulation too.

 

[biffvernon]

I can't remember where I've read this, but found this article that describes some old methods for preserving wood including - rather astoundingly - 'painting' or soaking in petrol. :shock:

I would expect about 100% of the petrol to evaporate, unless a match was applied first.

 

[Feltwell]

Given the current price of petrol, it would probably be cheaper to just replace the posts.

 

[Penners]

I would expect about 100% of the petrol to evaporate, unless a match was applied first.

You may have hit on idea there, Biff. Applying a match would almost certainly clear the woodworm infestation.