Roof rafter insulation

[geraldthehamster]

Richard,

Thanks, I do understand the issues and I will save a print-out of the dialogue that we have had for reference.

I went back to the house at the weekend and spent some time in the loft - more to do with a partition wall that I building for my son than to do with the damp in the ceiling.

However, I made a couple of observations whilst I was there. Firstly, the house and all the nearby houses appear to have no ventilation to the roof at all. At least, no vents of grills in the soffit boards. They all look completely sealed at the bottom of the roofs. I looked at the gable ends as well, just in case they were vented that way, but they are not. I can't see any obvious ventilation. Ever heard of that?

Secondly, I was wrong when I said that there was no felt under the tiles. I was correct that in some places there is nothing, but mostly there is a material that I don't recognise where the felt normally is. It looks like a brown oily paper stuffed with something that looks like horse hair.

I didn't tear any of this stuff off to properly examine it, but does anybody have any ideas what this might be? It's clearly doing the same job that felt is supposed to do.

Thanks again.

I don't know what your brown oily paper is, but somebody will.

Even though the soffits have no obvious vent, you might find that sufficient air gets in through gaps. If not, you can install soffit vents, which are just little round plastic vents.

Have you tried exploring the loft on a windy day to feel if air is blowing in and circulating anywhere?

I'd suggest asking a builder to have a look at it. Could be a bit hit and miss; a good builder, or one who is a friend, could give sound advice, but in my experience some builders are prone just to stuff holes in a fairly unscientific way.

Cheers
Richard

 

[paulp51d]

Thanks again. I may have a builder going there at the weekend, so I will see what he has to say.

Paul

 

[geraldthehamster]

Thanks again. I may have a builder going there at the weekend, so I will see what he has to say.

Paul

Make sure you come back here and tell us; I for one would be interested to know. It all adds to the general pool of knowledge

Cheers
Richard

 

[Ripperoo]

Make sure you come back here and tell us; I for one would be interested to know. It all adds to the general pool of knowledge

Cheers
Richard

I guess he forgot!

I would have been interested in this also.

Apologies for the TR!

 

[PaulP59D]

It wasn't so much that I forgot, more a case of not getting to the bottom of it. My son's father-in-law is a builder and he did not recognise the material under the tiles either.

There were no major problems in the loft, other than it generally being a huge mess with live electrical cables and strange wooden constructions holding a light in place and a ton of insulating material that just looked as if it had been lobbed up there.

So, we cleaned it up, boarded it, moved the boiler up there and left it at that. As for the material under the tiles that I was asking about: still no idea, but it seems to be doing its job.

 

[Xenon]

As for the material under the tiles that I was asking about: still no idea, but it seems to be doing its job.

Its Bitumen paper, looks like greasproof paper with a hessian reinforcing in it. Used to be used in the same manner as 1F felts.