Replacing felt and laths

[Chaang]

Hi,

My roof at this back is leaking (only coalhouse stuck on the house really). I have had a quick look and the felt is ruined (only checked the bottom so far) and so are some tiles.

I plan on getting the tiles off, seeing how many I need then replacing "felt" and laths.

What should I use for "felt" seems like I have a lot of choice now, insulated breathable etc? Where should I get tiles/laths?

Do I need anything else or should I just get cracking?

Cheers,

Mick

 

[Alastairreid]

Tiles, laths, breather membrane, ridge tiles? lead? eave trays, verge closers.

And some dry weather

 

[Chaang]

Tiles, check
laths, check
breather membrane, What type? Like this?

http://www.screwfix.com/p/vtec-high-grade-roofing-membrane-each/95578


ridge tiles? No need
lead? Dont think so, stopping before i get that high

eave trays, Maybe, is that instead of just running the felt in the gutter?
verge closers. Not sure what they are?

And some dry weather, fingers crossed!

 

[RedHerring2]

I don't where in Staffs you are, and it's a big county, but this place, near Norton Canes, has seemed good to me in the past:

http://www.smroofing.com/s-m-roofing-supplies.html

Also, for eaves trays, verge closures, other plastics in Rugely:

http://www.gbplastics.co.uk/Branch_Information

You can normally give some places like S M Roofing the dimensions and choice of covering and they'll work out all your requirements, etc.

 

[Chaang]

How do I fit the eaves trays? Surely they are under the laths?

The bit I am doing is about 2m by 2.2 m. Its just a coalhouse stuck on the back of the house.

View media item 40672
I have took some tiles off today and a lot are frost damaged So i have bought 100, some laths and some membrane.

Tomorrow I plan to strip the rest of the tiles, laths and felt and hopefully get some felt and laths down so it is a little bit weatherproof over night. I also have a bit plastic sheet I will nail down overnight.

I am hoping there will be some lead? where I meet the roof of the main house. The pitch of the roof of the main house is completely different so this is where I am going to replace everything from.

I am also concerned that some of the wooden beams that the laths are nailed to look rotten at the bottom (where the felt was rotten). I guess more will be revealed tomorrow.


Sound like I am on the right track? Anything I have missed?

Cheers,

Mick

 

[RedHerring2]

How do I fit the eaves trays? Surely they are under the laths?

Tomorrow I plan to strip the rest of the tiles, laths and felt and hopefully get some felt and laths down so it is a little bit weatherproof over night. I also have a bit plastic sheet I will nail down overnight.

I am also concerned that some of the wooden beams that the laths are nailed to look rotten at the bottom (where the felt was rotten). I guess more will be revealed tomorrow.


Sound like I am on the right track? Anything I have missed?

Cheers,

Mick

I've seen eaves tray fitted so that it fits over the lowest batten, but I've never been able to fit it like that. I've always fitted it so the lowest batten traps the eaves tray. This seems to create a dam at the bottom edege of the roof, but there shouldn't really be much water on the membrane.
The eaves tray overhangs the facsia by about 50 - 60mm, into the middle of the gutter. Obviously the membrane sits over the top of the tray, but doesn't need to reach to the bottom edge, otherwise there is the possibilty of it being visible when the roof is complete.

You'll probably find that you can fit your membrane in the same amount of time that it would take you to fit a temporary cover, so aim for that route. That alone will make it watertight. But also install at least every other batten to prevent the membrane disappearing overnight!
If you install only every other batten you may have to adjust the gauge when you fit the rest so it may be just as well to aim to fit every batten. It doesn't take long, if you have worked out your gauge and are prepared with spacers.

I've always installed the membrane with staples and then fitted the eaves tray under the lower edge, then fix the battens.

If you don't want to replace any rafters you can install a sister rafter alongside to strengthen it.

Edit: I suppose another method would be to install the eaves tray under the lowest batten, but allow the membrane to drape over the batten, leaving the lower tile to trap the membrane in that position.

 

[Chaang]

Well, Tiles and most laths are off. Problem is now its covered in snow!

Think I will give up for a bit. The old felt will keep most of the wet out.

Am I correct in assuming that the felt should run from top to bottom? At the moment it runs across.

Can I come back and fit the eaves trays later? I think some of the wood needs replacing but I think I will leave this til we have better weather and just take the bottom couple of rows back off.

Mick

 

[Alastairreid]

Fit the eave trays first, the tray sits on top of the fascia with a lip into the gutter, the rest up the roof.
the first course of felt then goes on top of the tray .

Then the first batten goes on. The felt sags slightly between the trusses allowing any water which penetrates the finished roof covering to run freely down and into the gutter.

Unlike felt the trays are uv resistant and do not perish so readily where they are exposed to the elements.

 

[RedHerring2]

The felt sags slightly between the trusses allowing any water which penetrates the finished roof covering to run freely down and into the gutter.
.

Just another clarification Alastair, I understood the OP was using membrane:

i have bought 100, some laths and some membrane.

Shouldn't the membrane be fitted taut?

The mebrane should be fitted across the slope, not up/down. Most membrane that I've seen has lines to show the amount of overlap.

 

[Chaang]

I am using protect a1 roof underlay. It says to leave "shallow valleys to allow drainage".

I have stuck my cover on and given up for today. Was far too slippy.

Ok, so I will go horizontal.

It does say on the packet to use an "Eaves Skirt".

 

[freddiemercurystwin]

Membrane should not be taut.

 

[Chaang]

Where can I buy 2 felt support trays? (without £12 postage!) I dont want a pack of ten?

 

[Alastairreid]

Where can I buy 2 felt support trays? (without £12 postage!) I dont want a pack of ten?

Just use a strip of DPC... builders merchants or one of the sheds.

 

[RedHerring2]

Where can I buy 2 felt support trays? (without £12 postage!) I dont want a pack of ten?

G B Plastics in Rugely.

Sorry for my confusing the situation, re taut or draped membrane.

I have now discovered that both applications are correct in differing circumstances.

My own confusion arose from doing my roof in France which was counterbattened over the membrane, (over insulation above rafters), due to the use of slate hooks. This is the correct method of taut membrane.

I then continued the practice of taut membrane, but without counterbattens, here in the UK on the garage (again over insulation above rafters) and on the extension. BCO did not mention any problem with it. In these circumstances I should have draped the membrane, allowing about 10mm of drape.

 

[noseall]

It does make me laugh when bco's and manufacturers insist on breathable felt being draped between rafters.
Try doing it when it is blowing a gale and you have membrane flapping about round your ears.