Roof eaves membrane - is this overhang normal?

[warwickshire_poacher]

We've just had our old Finlock concrete gutters replaced and as part of the work the contractors fitted a new layer of roofing membrane over new plastic eaves trays and under the first couple of rows of tiles. The membrane extends into the gutter to such an extent that when the wind picks up it lifts the membrane over the edge of the gutter.

Photos to show what I mean:
Pic 1 | Pic 2 | Pic 3 | Pic 4

Couple of quick questions:

1) Is this normal for this type of installation? I assumed that as there are plastic eaves trays to seal the gap between gutter and fascia [see Pic 3] the membrane does not need to extend past the last row of tiles?

2) My concern is that in high winds the rain could slide right over the membrane and miss the gutter completely. Is that likely or will the weight of the water push the membrane back down into the gutter?

3) I'm tempted to trim the membrane back in line with the bottom edge of the tiles - does that create a risk that water could be blown back up into the roof space?

At the moment it all looks a bit odd as you can see the fabric flapping in the wind from the garden, but if it's going to keep things more watertight I'll live with it.

Advice would be welcome!

 

[^woody^]

Membrane is normally cut back on line with the fascia, with only the eaves tray projecting into the gutter.

 

[datarebal]

Underlay support trays are fitted, Sharp Stanley knife trim the membrane back ..it'll rot off anyway

 

[warwickshire_poacher]

Thanks for the advice. I've had some suggestions to keep the membrane extending (just not as far) but as long as the eaves trays have been fitted correctly I figured it should be OK to trim back in line the edge of the tiles. I'll see if I can get up there with a stanley knife and give it a go.

Edit: a couple of the tiles are not sitting flush (e.g. Pic 3) - will that cause water to run inside or does it tend to stay in the centre channels?

Tiles 1
Tiles 2
Tiles 3

 

[noseall]

Aargh valley tiles! Stuff of nightmares. Prolly used shallow battens and cant get the tiles (close to the valley) to seat properly.

 

[^woody^]

It's bizarre. I can't think why they would have done something like that. Not even to cut off afterwards, as the membrane would normally be laid flush with the fascia line to begin with.

 

[warwickshire_poacher]

I assume it was to support the eaves trays and ensure rain water flows into the gutter, but it looks quite untidy. The builders next door said it's not uncommon for leave some of the eaves membrane extending out, but not to that extent.

I have asked for some opinions on another forum and they have suggested the tiles may not be far enough forward either. The roof was in a bit of a state anyway (we've only owned the house for 18 months via a probate sale, the previous owners bought off-plan in 1962) so I'm not 100% sure whether the tiles were properly aligned in the first place (but I would have expected the contractor to point that out to me before they started). I've not paid anything for the work yet so I'm hopeful we'll be able to get it sorted out fairly quickly, but it's useful having some pointers on what to raise.

 

[vinn]

The white membrane you have showing is, I should imagine, simply a new ripping of membrane. The old roofing felt would be black. Hopefully, this ripping was slipped under sound original roof felt further up the roof.

Your tiles dont come forward over the gutter by the approx 25mm thats common in my limited experience - I doubt that the first course of tiles can come any further forward because the tile battens, without a major upheaval, could not be adjusted after the Finlock was removed.

FWIW: The eaves trays are not supported by the felt - its the other way round. The trays support the felt as it covers them.
The felt was traditionally lapped into the gutter by about 25mm but, as above, its simpler to cut it at the fascia.
In your case, simply cut the felt slightly back from the tile butt.

Perhaps some of the alignment difficulties were caused when the eave trays were installed.

If you go into the loft & examine the valley from below I should imagine water staining or leaks will be noticed.
AAMOI: the discharge from the valley into the gutter is odd looking - have off-cuts of membrane been pieced in?

It also looks as though the installers got themselves involved in some sand & cement work in the valley - possibly due to moving the bottom of the valley to 1. cut the Finlock, & 2. to slip some membrane under at the inside corner - with things going bad from there.

 

[^woody^]

The builders next door said it's not uncommon for leave some of the eaves membrane extending out, but not to that extent.

It was common back in the 50's before they invented plastic eaves tray, but for the past 30 years or so no felt or membrane should be projecting into the gutter. It should be trimmed so that it stays covered by the tiles and protected from sunlight. And no builders or roofers should be saying otherwise.

And it does not matter where the tiles end or if they are not far enough forward.

 

[warwickshire_poacher]

Spoke with the surveyor at the company - he reckons once the membrane gets wet it will naturally fall into the gutter and stay there... obviously that contradicts the advice here so I will push back a bit and ask them for some more explanation.

 

[^woody^]

Spoke with the surveyor at the company

You must have spoke with the office cat surely, not the surveyor?

 

[Nige F]

Cats Rule

 

[freddiemercurystwin]

 

[catlad]

My guess is they left it that long in case of a down pour while they were
redesigning the gutters, why they have not trimmed it back afterwards is anybodies guess.

 

[datarebal]

it will sag when wet, but flap and bang when its windy.. cut it off, get rid of the valley tiles they will be leaking soon