What's going on here?

Lumen

Today I pulled down a load of cladding that formed the sloped ceiling in my front hallway. This part of the house is single story so this is the underside of a small roof section.

What happened?

There appear to be two sarking layers, the black (which has been torn by something) and what looks to be a newer possibly breathable membrane on top.

The other odd thing is that there are splashy mortar snots all over the rafter, which are not on any of the other rafters.

I have a roll of Solitex and tape handy to patch it, and I could try to cut patches and insert them above, and then tape over, but I'm not sure how much effort is justified given that there's the second white membrane there, presumably doing its job. I'm really NOT keen to lift slates, this was supposed to be a quick job.

The plan here is to partially fill with woodfibre insulation, put an Intello membrane over it (against the rafters), then add new cladding of some sort acceptable to the boss.

Man with broke phone

Id say the mortar is just from when they plastered the wall beside it.

Xtrail14

Remains of scudding.

Lumen

Thanks, I guess I mostly meant "how did the felt get torn?". Should I be worried that I have creatures in my roof space?

Should I try to fix the torn felt?

con747

Looks like its just degraded over time.

Lumen

It's just odd that it's only one section.

Man with broke phone

Could be just slight expansion and contraction of them two joists pulling it apart over time.

Stigura

Lumen wrote: »

Should I be worried that I have creatures in my roof space?

I've never seen anything like that, caused by creatures.

My instinct is to question what's to the right side of that right hand rafter. And to ask what / why is that one bit of wood so 'dirty'. What's that stuff on it?

Lumen

I have a theory!

On further probing it looks like the mortary stuff is all over the topside of the busted felt too, and it's properly thick there, not just splatter.

It's almost as if a jet of plaster came from the sky and burst through the felt, somehow missing the slates.

So my uninformed theory is that when the house was built, the roof was framed and felted but not slated, and in that period the wall above it, or the perhaps the verge of the adjoining roof was being plastered/cemented. Some fool dropped a bucket of plaster/cement on to the unslated roof felt, and through it burst, splattering the rafters in the process.

They then added another layer of felt over the top.

The weakness in this theory is that the white membrane looks much newer. So perhaps it will remain a mystery.





Anyway, I taped it all up so at least it doesn't poke into my ventilation gap above the forthcoming insulation.

tabby aspreme

Is there 2 layers of lead flashing on the left side of the last picture, it looks like there is a bellcast behind the lead. During building, the house roof would have been felted and lathed, the cover flashing tacked to the wall and plastered over with a bellcast on the plaster , then when the roof was tiled, the flashing was lifted enough to get the soakers behind it. The cement on the felt is spattered scudding, I would think that part of the roof had the tiles removed for some reason, hence the second layer of lead and modern membrane. The original plaster covering the flashing was probably damaged when the tiles were removed, and another flashing put over it and cut into the wall.

Cerco

Maybe it was a leak which caused the felt to degrade over time. The water may have cause the membrane to sag and eventually tear. The new membrane was the repair. Was this area under the lead flashing?

Stigura

tabby aspreme wrote: »

spattered scudding

Makes me think of the morning after.

Lumen

Cerco wrote: »

Was this area under the lead flashing?

Yes.

Xtrail14

It’s mortar droppings from the side gable plastering. Gable was plastered before tiles were fitted. Plasterer’s are a wreck for scudding.

Lumen

tabby aspreme wrote: »

Is there 2 layers of lead flashing on the left side of the last picture, it looks like there is a bellcast behind the lead. During building, the house roof would have been felted and lathed, the cover flashing tacked to the wall and plastered over with a bellcast on the plaster , then when the roof was tiled, the flashing was lifted enough to get the soakers behind it. The cement on the felt is spattered scudding, I would think that part of the roof had the tiles removed for some reason, hence the second layer of lead and modern membrane. The original plaster covering the flashing was probably damaged when the tiles were removed, and another flashing put over it and cut into the wall.

Interesting. Not sure about the two layers, here's a close up.

I think the newer membrane suggests a roof repair as you say, but the really curious thing is the combination of splatter and the hole, suggesting to me that the splatter happened after the hole was made, or at the same time.

It's almost like the hole was made during original construction, covered up by a builder, then water damage developed over time, so the slates were then lifted, the problem discovered and the second membrane put over.

listermint

The bitumen style felt you are seeing from the inside is the original felt. I've the same on my roof and the same damage. It degrades over time dries out and cracks and falls apart.

Someone removed all those slates at some point put in modern breathable membrane over the original felt and the put the tiles back down. small enough job ....you have nothing to worry about it's weather tight with the new stuff just looks a bit ****e inside with the old stuff.

Most folks would have removed the old stuff but that guy left it.


I've on my project board to redo my roof because the bitumen is in bits all over the shop. Not surprisingly it's in there 50 years.