Tiny flat roof repair

[Pete.]

I have the smallest of flat roof repairs to make. This felt roof has been in place at least 34 years and I want to replace the timber and the felt. Here's the job in question:





So far I have got:

1 sheet of good quality plywood
1 roll of industrial quality torch-on felt
Big roofer's torch, small propane torch and a bottle of gas.

Plan is to remove the gutter, rip off the felt, remove the fillet and old floorboard roof deck, cut ply to shape, fix onto the existing joists, fit new fillet and then re-felt over the top.
I have to get a roll of underlay and a roll of torch-on capping but before I go buying stuff I need some advice on how to go about finishing the felt onto the timber lintel and the drip edge above the gutter.

Planning to fix the underlay with clouts, torch the mid-layer onto that and then torch the mineral layer on top of everything. What I have no idea about is how to finish the top and bottom edges. If I over-hang the ply sheet to the same extent as the existing roof how do I go about forming a drip-edge? When I fix the new ply sheet do I trap a strip of the underlay under the edge so that no plywood is left exposed? Will that be sufficient.

Old houses eh

 

[gaz1]

sorry you cant use the torch as you will melt the plastic roof that you have on the left

normally its @roofman but i believe he will say the same as me you will have issues

no offense but which moron didnt fit lead under the soil pipe

 

[Pete.]

None of it is my works so no offence taken

I lived here as a teen when my parent's rented it then later on bought the house and it's neen that way for as long as I can recall. I will lift the plastic roof to do this, or protect it with a welding blanket or something.

 

[gaz1]

you will have to lift it so sort both out at the same time

more work but could be done way better

but need a wider photo shot

 

[awemawson]

Do the whole roof as a single sheet of lead thus avoiding most of the issues raised. I may have a bit big enough Pete so text me sizes. Also I'd rebate lead flashing into the wall to overlap the roof upstand.

 

[Gareth J]

Insulation between joists while you're in there?

 

[Pete.]

Insulation between joists while you're in there?

Yes of course if there's room. Don't want to fix the leak only to rot it out from the inside.

 

[Agroshield]

Please have a look at these and see if they might be suitable or if the concept gives you some ideas:

Flat Edge Drip Detail Cold Roof - Hambleside Danelaw

Here you can find the PDF and DWG files for Installation of a typical flat edge or drip edge detail with the Dryseal flat roofing system.

www.hambleside-danelaw.co.uk

https://nhbc-standards.co.uk/2019/7...and-balconies/7-1-10-detailing-of-flat-roofs/ (Welted drip to external gutter)

Flat Roof Penetrations: Best Practice

Flat Roof Penetrations are a cause of weakness in many roofs - get them right! Read our advice and view our details showing best practice.

www.singleply.co.uk

The singleply one looks like an upside down bit of edge trim as used on holorib decking.

 

[Pete.]

Please have a look at these and see if they might be suitable or if the concept gives you some ideas:

Flat Edge Drip Detail Cold Roof - Hambleside Danelaw

Here you can find the PDF and DWG files for Installation of a typical flat edge or drip edge detail with the Dryseal flat roofing system.

www.hambleside-danelaw.co.uk

https://nhbc-standards.co.uk/2019/7...and-balconies/7-1-10-detailing-of-flat-roofs/ (Welted drip to external gutter)

Flat Roof Penetrations: Best Practice

Flat Roof Penetrations are a cause of weakness in many roofs - get them right! Read our advice and view our details showing best practice.

www.singleply.co.uk

The singleply one looks like an upside down bit of edge trim as used on holorib decking.

I have a SiG nearby I might take a trot down there tomorrow and ask them what they can supply for me.

 

[Pete.]

Got the felt off and I find that the roof is not only insulated but it's actually very sound apart from the leading edge which was rotted away due to being exposed. I have some identical boards stored in the loft for repairs so I am changing my plans. Instead of pulling it all off and replacing the boards I am going to remove just the edge and one more board (which is rotted on the end), replace it like for like and then put on the felt.

 

[jenki]

I think awemawson is right use a sheet of lead with all that plastic around a roofing torch is dangerous useful on large runs but very difficult in cramped areas. Possibly EDPM might be cheaper and is a cold process.

 

[gaz1]

lead is the old way grp is the new way

i think pete is going to have trouble with that lot as the whole thing is a mess could do with adjusting made better but that means a whole strip down of both roofs so access can be gotten to both sort out the felt roof by torch then and then sort the plastic roof out by adjusting its height at the front

therefore both can be accesed in time for repairs

 

[angellonewolf]

ive done fiberglass roof with gaz help on that size roof would be easy and a near permant fix

the thread is on the fourm and got a link to vids on how to do it there is a series of 5 i think id wached them 3 times before going ahead and it was worth it

 

[gaz1]

ive done fiberglass roof with gaz help on that size roof would be easy and a near permant fix

the thread is on the fourm and got a link to vids on how to do it there is a series of 5 i think id wached them 3 times before going ahead and it was worth it

more roofing problems on the forum fixing this roof what way ?

after having problem with my roof for a few years since we moved in on the extension its a flat roof with a slope runs away fine with little puddles on the roof when raining but i keep having water marks on the inside near the house on the plasterboard near the joint between the house and the...

www.mig-welding.co.uk

 

[Pete.]

Thanks for the advice but things are moving in a definite direction as I want to get this done today. I've now got a roll of 4kg underlay and a roll of 5kg mineral, 3m of 300mm lead flashing and about 5 hrs to get it all finished.

It'll definitely be an amteur job but then - I am an amateur. Demolition is my speciality. At least if I mess it up I won't have too much grief taking it all out again

This is where I'm at now:

 

[Bobtail4x4]

wish you were closer, I have enough grp and trims left over to do that small roof.

 

[gaz1]

Thanks for the advice but things are moving in a definite direction as I want to get this done today. I've now got a roll of 4kg underlay and a roll of 5kg mineral, 3m of 300mm lead flashing and about 5 hrs to get it all finished.

It'll definitely be an amteur job but then - I am an amateur. Demolition is my speciality. At least if I mess it up I won't have too much grief taking it all out again

This is where I'm at now:

View attachment 307822

screw a trim on under the edge lath or 1x1 wood trim the thickness will give you something to fasten too as well either nails or melted on itstead of a small edge

 

[gaz1]

if torching it on

do the up piece first small off cut and torch it on then roll out and torch that on and then torch another small piece for the upstand point and another roll out finish off with another edging trim

the edging trims for both the side and rear piece

then you have 2 coatings of torch on felt

 

[Gritineye]

no offense but which moron didnt fit lead under the soil pipe

Soil pipe installer cut the step flashing off, bits still there in the course above.

 

[Pete.]

if torching it on

do the up piece first small off cut and torch it on then roll out and torch that on and then torch another small piece for the upstand point and another roll out finish off with another edging trim

the edging trims for both the side and rear piece

then you have 2 coatings of torch on felt

Gotcha, I will do that, or some close variation thereof. I need to put an extra layer towards the back anyway to help prevent pooling.

Underlay is on, here is where I'm at. I'm sure that 'pro' roofer's don't have to use a tack stapler but I sure as hell did then went around it with clouts.



Made one little bog-up, I'm sure it won't be the last. I didn't allow for the far right corner.