Eaves Guard

[Delinquent]

What's the general consensus on Eaves guards - do you go for a rigid PVC type tray, or a roll of wide DPC tacked under the edge of the felt?

I have enough DPC to do the job sitting here free and am somewhat loathed to shell out £50 on some flimsy bits of plastic unless really necessary!

[chappers]

have used both in the past but now use roofing under felt, a bit more riged than dpc but a lot cheaper than eaves trays

[Delinquent]

cheers chappers.

[^woody^]

Roof felt (or membrane) rots in a few years where exposed, and sags between rafters

Use a proper UV stabilised plastic

[chappers]

not when nailed to each rafter and then tyveked over.also i have stripped roofs that have been undersarked with roofing felt and the only place it has rotted has been where it has turned down int the gutternever under the actual roof covering and certaily not past the first batten.

[^woody^]

Felt or membrane will be attacked by the weather and UV where it is exposed - ie the bit that drapes into the gutter. When this rots, water misses the gutter and either runs down the fascia or back along the soffit and into the room.

[noseall]

Delinquent wrote:

What's the general consensus on Eaves guards - do you go for a rigid PVC type tray, or a roll of wide DPC tacked under the edge of the felt? I have enough DPC to do the job sitting here free and am somewhat loathed to shell out £50 on some flimsy bits of plastic unless really necessary!

we use 12" plastic dpm.

chappers, the whole point of the more robust eaves tray is that it reinforces regular underslaters felt at the eaves/gutter detail.

underslaters felt rots off at the exposed fascia top edge directly beneath where the eaves tile rests upon the fascia.

why on earth then would one use underslaters felt to reinforce rotting.....er..... underslaters felt.

[chappers]

Don't use it for that purpose, use it to support a breathable membrane.
I know as woody says that membranes are not garaunteed UV stable for more than a few weeks, but in reality they don't actually disintergrate like felt.
In all truth it should be pretty irrelevant as the primary roof covering should be sufficient to weather the roof.

[noseall]

chappers wrote:

In all truth it should be pretty irrelevant as the primary roof covering should be sufficient to weather the roof.

this is my view too

http://www.diynot.com/forums/viewtopic.php?t=145259

but, if i were to recommend anything i would say a 12" plastic dpm is as good as anything.

[nosemitemos]

Are we speaking about 5U under eaves felt,with no string in it for the water to rot :Felt support trays are normally only used when there is no sarking or boarding on roofs and on this instance usually the felt is normally cut back to the fascia board

[mrcrow]

^woody^ wrote:

Felt or membrane will be attacked by the weather and UV where it is exposed - ie the bit that drapes into the gutter. When this rots, water misses the gutter and either runs down the fascia or back along the soffit and into the room.

this is my problem..i came to ask about this and here is a post all about it
good!

i thought of buying some dpc since the front of my house gutters have been fitted with this
the section at the back where the roof felt was originally hanging into the gutter has all broken up and some water is getting into the soffit board area which i am draining out with a little hole till the job gets done

i understand i have to lift the tiles at the eaves and push the dpc UNDER the felt..i am going to take off the gutter to do this

any further advice appreciated

mrcrow
manchester

[bobtheb]

This is advise from the NHBC
Question
Can plastic dpc material be used at eaves level in place of a type 5U felt?
Answer
Dpc materials should not be used for the exposed sections of roof underlay at the eaves. Plastic dpc materials are generally not designed for use in permanently exposed locations. The lack of suitable ultra-violet stabilisers could lead to an early breakdown of these materials in such locations. A type 5U felt should be used for the exposed sections unless the underlay used for the remainder of the roof has a third party assessment confirming its suitability for use at exposed eaves. Alternatively a proprietary eaves guard which extends under the unexposed section of roofing underlay and provides adequate projection into the guttering may be used.

I would say there is some confusion between types of 'Felt'. 5U felt is not the same as the old style felt which rots fairly quickly when exposed to sunlight and constant damp: 5U felt is a polyester reinforced bituminous eaves protection sheet designed to be dressed into the gutter prior to the installation of the pitched roof underlay. Roofers nowadays use breathable membranes under slates or tiles, this is not UV stable for more than 4 months. You could use UV stable plastic eaves guards/carriers designed for the job but these may be more expensive and don't last for ever. You might even use lead for a Rolls Royce job. Whatever you do, the eaves guard must be tucked under the membrane/underlay/old felt by at least 150mm depending on the roof pitch. Not doing all these things risks water entering the building.

[shane12345]

I use 15 inch DPC then start first run out of felt just above the fascia.

[bobtheb]

Plastic DPC degrades in sunlight because it is not designed to be exposed to UV rays. You'd be better off using 5u felt for the bit going into the gutter and then using breathable membrane for the rest of the roof. Breathable membranes are better than bitumen felt for the rest of the roof because they breathe and you don't have to ventilate the roof space, this also makes the house warmer. Look up DuPont Tyvek or Kingspan Nilvent for more technical information. The devil is in the detail.