Removed Lath & Plaster from Cellar Ceiling

[oioi727]

Hi all,

I live in a house around 120 years old. Ceiling in the cellar had lath and plaster. Typical cellar moist and dampy…

The room above the cellar in north facing and I want to insulated between the joist with 100mm Celotext Rigid Foam foil back insulation (bought them cheap before the prices went up)

I think I need to treat the joists and if so what would you recommend. See photos.

P.S I have added an extra air vent Agee years ago to improve air circulation.

 

[JohnD]

Cuprinol 5-star is very good, though not cheap. You may find an own brand cheaper. There are garden ones for external use, I imagine this is to keep fumes outside while they dry. Look for both an insecticide (against worm) and a fungicide (against rot). Treat the ends of the timbers against external walls most thoroughly. Scrape and vacuum all dirt and other matter off first. If the timbers away from the walls are dry and well ventilated they should not be at such risk. Prod them all with a flat screwdriver. Nothing pointed or round because the marks will look like wormholes.

Bear in mind that these biocides are intentionally poisonous. Read the manufacturer's documentation, and you should find the Hazards warning that tells you what the ingredients are.

So protect yourself well, especially skin and breathing. I wouldn't spray, above my head and in an enclosed cellar, unless I had one of those helmets with blown fresh air hose.

It will tend to drip on you from a brush. if you took the floor up it would be easier.

Presumably you are improving throughflow of air through the cellar to blow away the damp air and reduce humidity. How will you do this? It will keep the walls and floor drier if you can evaporate and blow away the water faster than it arrives.

What does "Agee years ago" mean?

 

[oioi727]

Hi John, thank you for such a thorough reply.

The text should have read “a few years ago”.