Attic conversion, questions. Damp white spores on rafters

[compact]

Converting attic to regs and ok standard.
Not wanting to take tiles off, couple of questions.
1 Should I put a membrane on the inside before I add insulation between the rafters? The roof seems good and no obvious leaks in the past.
2 slightly counter to last comment, I've white spores on the rafters near the ridge. It's dry to the touch, Aldi moisture meter reads around 27% on most rafters but some (along with some places on ridge beam) are off the scale.
My thoughts are the ridge needs re bedding/pointing.
But what to do with wood. Clean, sand, any treatment for the wood?
3 I need to build up party wall between for fire, but how exactly do you do it, up to tiles? Seal against them?

A couple of photos below
Thanks

Untitled

• compact
• 7 Nov 2014
• 1

Untitled

• compact
• 7 Nov 2014
• 1

 

[catlad]

The staining is nothing to worry about in my opinion it will probably be leaching out of the ridge tile cement, and if you are converting then change it for a vented ridge system.

 

[freddiemercurystwin]

The staining is nothing to worry about in my opinion it will probably be leaching out of the ridge tile cement, and if you are converting then change it for a vented ridge system.

Why? There's no felt, the roof couldn't be any more vented. Or do you mean fit a vented ridge if he's gonna re-bed the ridge anyway?

Don't bother with a membrane. You may have to get BC to give the nod to your roof before you proceed, sometimes if they think the roof is poor they will get snotty about the lack of a membrane.

Build the party wall up in a single skin of block in line with your side of the PW.

Something like http://www.rockwool.co.uk/products/...nsulation/intumescent-expansion-joint-sealant would be OK for the joint. Your local merchant will prolly have something similar if not this. Or there are intumescent sealer's. Obviously avoid an intumescent expanding foam.

 

[compact]

Cheers for the quick replies.
You're right that some of the white is from the dementia, however there was definitely some spores / damp as well. I've sanded them and have been recommended using Cupinol 5 star on them to kill off anything and help for the future.??

When you say build up block wall on my side. I was hoping to keep the shape of the chimney, battoning around and plaster boarding as it looks interesting.
Could I just build up the skin of bricks on my side?

I've some determined flies up there, checked everywhere and can't find the source. Must be from the neighbours.

 

[catlad]

I was under the impression that a re-slate would be on the cards due to a loft conversion. You can get smoke bombs to kill of the flies.

 

[compact]

Why would you re slate if it isn't leaking?
Are there any regs I'm missing?

 

[freddiemercurystwin]

When you say build up block wall on my side. I was hoping to keep the shape of the chimney, battening around and plaster boarding as it looks interesting.

Ahh I see what you mean, I thought you meant the whole PW was missing (as is sometimes the way) but I can see now you mean the wall has not been finished flush with the underside of the roof. You could use something like http://www.fireprotectiononline.co.uk/fire-resistant-mortar.html and then seal up the final gaps if any with some intumescent mastic. It might be advantageous if you had access to the other side when you do it.

 

[freddiemercurystwin]

Why would you re slate if it isn't leaking?
Are there any regs I'm missing?

No but you should mention to your BCO that you don't intend on re-roofing, he may wish to inspect the roof beforehand.

 

[catlad]

No you don't have to re-roof but if steels are going in and dormers are being constructed and then rafters not being deep enough then its normal to upgrade the roof.

 

[compact]

Cheers
No steels for the actual roof (though for the joists)
No dorma just velux.

I spoke to them today and they're fine with it.
So handing in the forms and seeing if they will pop out anyway, as always good for a once over before its too late.