Extremely dirty eaves space - is it possible to clean rockwool, I should I replace?

[Ges1]

Hi everyone,

Trying to figure out the best course of action here. I have plans to lay a floor in my eaves space, just to make access a bit easier for some eaves cupboards I plan to build down the line, and I'm concerned about the absolute state the previous owners left the space in. Take a look:

Now, as far as I know, and I'll be confirmed this with the plumber, I can remove most of these pipes, so that's not a problem. My problem is for whatever reason they chose to plaster 50% of the place while leaving all of the offcuts behind, the result is that the entire space is absolutely filthy. The picture doesn't really do it full justice, it's basically a building site. Our bedroom is on the other side of the knee wall.

Could anyone advise on whether it's possible to clean rockwool, or should I just rip everything up, bin it, and replace with brand new? Ideally, I'd clean the wool up as best as possible and then just lay by P5 over the top, as it'll cost me less money.

The house is a 1900 cavity wall, and it's a cold loft.

Thanks!

 

[Ges1]

Hiya, thanks for the reply.

I have a combi boiler, so the cylinder isn't a consideration, but my main thing here is that I'm not trying to complicate things, I'm just trying to find out if I should clean this rockwool or replace it completely.

 

[Ges1]

Nevermind, going to replace the whole lot, bring it up to 270 with some loft legs and then board over that instead. Easier to just roll up the old crap and start again.

 

[Old Salt]

My loft was similar when I moved in. I just removed all the crap and worst of the dirty / torn loft insulation and then added fresh stuff over the top. Although the old insulation looks bad it must add some value and a lot easier to lay new insulation over the top than removing the old.

 

[Notch7]

Nevermind, going to replace the whole lot, bring it up to 270 with some loft legs and then board over that instead. Easier to just roll up the old crap and start again.

What you have is fibreglass not rockwall, but it’s way under spec, so replacing it with 270mm is a good decision.

Wear a mask and long sleeved top when removing it, it’s proper itchy stuff

 

[Ges1]

Cheers mate, already back from Wickes! Did exactly that (went with glass again because it was half the price).

This is going to be an awful job. I grabbed myself a full body suit while I was there. 9 quid well spent.

 

[JohnD]

went with glass again because it was half the price

Which product did you buy?

Wickes.co.uk

Search results for Insulation on Wickes.co.uk

www.wickes.co.uk

 

[Ges1]

I got knauf bottom layer 100mm, and then a 170mm top layer

 

[Old Salt]

Wear a dust mask and disposable gloves. Wash off bare skin in cold water after you finish. It closes the pores. The new stuff is probably not as bad as years ago but it wont hurt to be careful.

 

[JohnD]

The Knauf product is treated with Ecose, which prevents it shedding irritant dust and fibres.

I would never have the old yellow fibreglass again. I recommend bagging it up while wearing a mask, carrying the sealed bags outside for disposal, and hoovering up the dust and fibres with a canister vac before starting afresh.

 

[Ges1]

Thanks, I’ve got an HEPA extractor with a brand new bag ready and waiting. It’s going to be a slow, terrible job, as the ceiling is lathe, but I think I’ll be glad I did it in the long run.

I’ve got a coverall, gloves, mask, and goggles. Going to seal myself in the loft and bag and vacuum as I go, then once I’m sure there’s nothing left to remove, I’ll bring everything down in one go. Hopefully I can get it done in a day.

Then to the opposite side of the house to do the other eaves argghhh

 

[Ges1]

Christ, this is horrible work. Respect to anyone who does this for a living.

 

[JohnD]

Doesn't look like much headroom.

If you just want crawl access for maintenance, you might consider cross-battening with timbers on edge, at right angles to the existing joists, and b9ard on top. This will spread the load and add rigidity, and you can lay your insulation between the joists in the two directions. I used decking timbers which are pretreated and quite cheap.

You can skew-screw the timbers together.

Don't use nails in a loft as your hammering may loosen the old plaster.

You can also lay decking boards across the old joists and screw down but this will not give extra depth. It is important to screw down loft boards or one day one will shift and you will fall through the ceiling.



There is a way of repairing old L&P from above before it falls down.

If you have any loose or cracked sections I can explain it.

Now would be the best time, while it is exposed from above and cleaned.

 

[Ges1]

Hi John,

Thanks for the advice, the lathe is all platerboarded over from the other side, so I assume that means it's OK to leave it? I bloody hope so! There's not much headroom, you're right, but thankfully there's enough to move. I'm going put some loft legs in and then board the whole thing over eventually. It'll give me just enough room to slide around on my knees!

That being said, if you think fixing broken lathe is a good idea regardless, I might just go ahead and do it; I'd say 90% of it is good, but there's a couple of bits that are certainly very bad

 

[JohnD]

You clean the upper surface thoroughly, remove any broken pieces, put a large flat board under the ceiling and press it up with a deadman to correct any sag, screw Expanded Metal Lathing to the sides of the joists in a tray shape, with the flat against the ceiling, and pour a thin runny mix of fine hard plaster over to cement the old ceiling to the new lathing. Once set, remove the supporting board below.

Old L&P ceilings are very liable to sag and fall down. The laths may be perished or rotted, and the old nails have have rusted to nothing.

I learned this technique many years ago, using Sirapite plaster which is no longer available. I expect there is some modern equivalent. I suppose you could do it with expanding foam.

It is done in the restoration of old houses, including Hampton Court, but is easy for any amateur to learn without needing special lime or plastering skills, if you are willing to spend the time.

The supportive board beneath means you can trowel it into place without fear of the weight pushing the ceiling down.

Interestingly (?) I formerly had an old house damaged by a burst pipe in the loft. One ceiling kept dripping, and we discovered that water had penetrated the original lime ceiling, and was lying in a lake in top of the skimmed plasterboard layer beneath, and dripping through lighting fittings.