Reparing pitched roof internal felt - from the inside?

A section of the felt is missing from the inside of my pitched, tiled roof. It's about a 2 mtr length, and two rafter-spaces wide. The tiles are the fairly common large concrete type and the roof has 4"x2" rafters and standard 1" battens. Is it feasable to restore the missing felt from the inside, without removing roof tiles? Alternatively, is there another way to affect a repair (expanding foam, perhaps)? I mainly just want to keep cold wind from entering the loft between the tiles in that area.

Thanks,

Jake

Reply to
JakeD
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A temporary patch yes, by tacking the felt (or even a plastic sheet) to the underside of the tiling battens (which will let in the rain in the event of tile damage) - but a permanent repair will require the lifting of tiles and battens in the affected area.

Even if you carry out a permanent repair, you won't stop the wind blowing into the attic - simply because of the way the roof is constructed - besides, some 'draught' in the roof space is required to prevent the build-up of interstitial condensation on the underside of the roof felt.

If you are trying to keep the heat in the property, then you would be far better off filling the roof space with around 280mm of loft insulation and insulating any pipes and tanks there against freezing.

Cash

Reply to
Cash

"Cash" wrote in news: snipped-for-privacy@mid.individual.net:

Thanks... I've already got the pipes lagged - and 280mm of loft insulation, thanks to B&Q offering the stuff for £3 for 3 rolls at present. But it does seem extremely drafty up there, when the wind is blowing, which must be leeching warmth from the house, despite the insulation.

Al

Reply to
JakeD

Not really Al. As long as the attic trap door also has the same thickness of insulation fixed on top of it - and draught strips to seal the trap door where it sits on the frame.

Also, it really is a good thing to have an airlow in the attic - hence the soffit and roof vents that are fitted to many houses these days that have good loft insulation.

As a matter of information: My wall cavities are filled [1], my loft is fully insulated, the trap door covered and sealed with a draught strip and all roof sarking felt intact - yet there can be what appears to be a force

10 gale blowing around up there, with the temperature at or below freezing, yet the bedroom that I now use as computer room-come office, is a nice comfortable 65° without the C/H on and around 74°when SWMBO turns the heating on.

All bedrooms, landing and bathroom are the same - and all bedroom rads have thermostatic rad valves fitted.

[1] As an old builder, this was done against my better judgement, but retirement and increased heating costs sort of forced the issue - and I must admit, the job has certainly cut my heating costs. All I'm waiting for now, is for my old Baxi wall boiler to pack up, which because of the shortage of some spares, will force me to replace it with a new condensing boiler.

(It's not cost effective to replace it now just to 'save' some money on gas, because of the length of time it takes to recover the capital outlay of the boiler in energy saving costs).

Cash

Reply to
Cash

without

Such a temporary patch can be pretty effective at keeping any wet out though. The weak points are the holes you need where a batten crosses a rafter. Everything else can be lapped such that any water that does get onto the felt can find its way to the gutter.

The lapping is a bit complex to explain but essentially the top of the new bit over laps on the loft side of the old at the top and sides. The sides need to be formed so that water will tend to stay on or move to the middle of the new. The bottom needs to be over lapped with the old on the roof side. you should able to push it down the gap between a batten and the old felt. Each rafter gap will have to be dealt with individually, think about how the joins at the rafters over lap.

Reply to
Dave Liquorice

I concur with that Dave - I've done it many times after storm damage, and I used to form a trough in the "felt patch" and aim this into a rather large container below to catch any 'loose' water until a 'proper' repair could be done, rather than try and re-direct it down to the gutter.

Cash

Reply to
Cash

crosses

Once the water is on the new felt with the bottom of that slipped between the old felt and batten at the bottom it should find it's way to the gutter, just as any other water on the felt would. As you say form the new felt into a shallow trough so water will flow down the middle rather than the edges where it might find the holes required at the batten/rafter intersections and it will be almost as good as contigious felt.

I had to work all this out during a storm when the only roofing was the old felt. the slates where all off as the roof was in the middle of being relaid by others. The wind got under the old felt and started ripping it off, fortunately the new battens had arrived and I had some long enough nails to "batten down the hatches" but not before there where a number of rips/tears in the felt.

Reply to
Dave Liquorice

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