Need some roofing help.

[MickCheese]

Hi

I hope someone will have some ideas to help me.

I have a workshop at the side of my house. It was built be the previous owner I merely inherited it.

Instead of the roof running away from the house it runs towards the house and has a box gutter between the house wall and the roof, an absolute pain.

Well, the metal box gutter is rusting and water is getting into the workshop. It's about 125mm tall and 150mm wide.

Access to it is not straight forward as the flat roof of the workshop overhangs it one side and the small sloping roof that forms a runway to the house wall over hangs it from the other so the opening to get into the gutter for cleaning is about 75 - 90mm.

My thoughts are to line the gutter on the three sides with 6mm marine ply that has been painted and then use something waterproof to stick over the ply to make it watertight.

My thoughts are either some form of flashbanding or some pond liner.

Does anyone have any better ideas?

Mick

 

[Jacob]

Bodging it from the outside doesn't sound too good, basically because you have to get flashings etc under the roof material (slates or whatever). Marine ply won't last long in the wet either. You probably should lift quite a lot of roof off and rebuild the gutter properly - structure underneath + plastic guttering + lead flashings + good fall over the length.

 

[AndyT]

What Jacob says is right, but my reading of your post was that sorting it out properly would mean rebuilding the workshop roof which makes it a big job, especially if it's leaking in the current heavy rain.

So taking your idea of a new lining for the box gutter - maybe upvc soffit board would be better than marine ply - and probably cheaper. If you use pool liner it ought to be feasible to lift the edges of the flashing and the roof and tuck it well in.

Do bear in mind that I'm a diyer not a roofer - and maybe a few pictures would help the ideas flow.

 

[kostello]

I think the easiest way to do it is either with fibreglass or some self adhesive EPDM.

I think you are in Wycombe?

Roofline in sands keep fibreglass roofing materials in stock along with the trims etc........

I used it a few times and if I'm local (i'm in totteridge) I don't mind popping over to take a look........

 

[MMUK]

If replacing the box gutter is not an option (you can get extruded aluminium ones for conservatories with plastic coverings for the underside), line it with lead. Code 3 will do but Code 4 is much better. Don't use strips more than 4' long and allow overlap of at least 8". Seal the joints with proper lead sheet sealant.

 

[Graham Orm]

Not easy however you do it. Repairs will inevitably need repairing again. If you want a new box gutter try a conservatory fabricator, they use them a lot made from aluminium. Maybe some sort of paint on rubber sealant if you can get in to do it for this winter then replace next summer. Roofing suppliers usually carry all sorts of fairly tough stuff that can be applied in the wet.

 

[MickCheese]

Jacob, I appreciate your input. You are absolutely right but it is a relatively new roof and I am loathe to lift it if I can help it. It maybe that if my 'bodge' does not work then that will be the only option.

I cannot get to the underneath as it is boxed into the fabric of the workshop.

Here are a couple of snaps taken standing on a wet slippery chair so not the best but may give you an idea.

I like the idea of using something that is not wood and prone to rotting so a plastic liner seems worth investigating. I did think of forming a glass fibre one in the existing gutter.

Thanks for taking the time to respond Andy and Jacob.

Mick

 

[MMUK]

Another thought. You could try some 6" soil pipe cut in half and laid into the box. You can pack it up at one end and taper it off to create a greater fall. Just make sure the edges are overlapped by the roofing material either side, or flashed over if it abuts a wall.

 

[Graham Orm]

Another thought. You could try some 6" soil pipe cut in half and laid into the box. You can pack it up at one end and taper it off to create a greater fall. Just make sure the edges are overlapped by the roofing material either side, or flashed over if it abuts a wall.

That would work....or commercial 6" guttering for that matter.

 

[MickCheese]

As you can see from the photo's it has two corners what you can't tell from the pics is the width and depth of the gutter.

I agree that whatever I do will probably not last too long so I think I am destined to remove it and start again.

I just don't understand what anyone would use a box gutter when making the room just 4" narrower and having a standard gutter on the other side would have been so much easier.

What you cannot see in the photo's is there is a down pipe in that zig zag corner.

Mick

 

[MickCheese]

Thanks all for the ideas, I am sure somewhere in this is a solution that will at least get me through to next summer when I will probably have to do it properly.

It's my wifes workshop and she is nagging me to sort it.

Mick

 

[kostello]

If you can get good access with a paint brush and can clean the dirt off the surface properly the fibre reinforced gloop in a can which can go on in the wet could easily get you another 5 years if done properly....

 

[MickCheese]

If you can get good access with a paint brush and can clean the dirt off the surface properly the fibre reinforced gloop in a can which can go on in the wet could easily get you another 5 years if done properly....

I have tried that but the gutter just rusted away from it in a matter of months.

Good suggestion though.

Mick

 

[Peter Sefton]

I have used fibre glass in these situations but as said before making the connection to the flat roof will be tricky.

 

[kostello]

I think fibre glass is the way to go if it is the size you say.

You can buy preformed angles and corners so you only have to glass the joins rather than try to form it all in place

 

[Cottonwood]

You could possibly reduce the roof height by 6 or 8 inches, enough to allow a regular unconcealed gutter and down spout on the house (bungalow?) and then have the shed roof re-pitched opposite to what it is now, to drain to the left (in the pics) with a regular gutter and down spout outside? Everything out in the open, easy to clean and repair in the future. But if it is a bungalow then you may have maxed out with headroom already....and it might not be feasible if reducing the height would interfere with window/door linttlels. The person/s who designed and built this werent thinking in terms of easy maintenance were they!

 

[Peter Sefton]

I do hate internal gutters and have inherited two leaking ones in the past so I do sympathize.

 

[MickCheese]

Thanks for all the help.

I like the idea if preformed glass fibre.

Will look into this.

Mick

 

[kostello]

Search cure it GRP roofing for what's available

 

[blackrodd]

I fixed my squeaker father in laws box gutter with aluminium from a caravan.
It's easy to bend in the workmate to the right size/shape, join the 48" lengths by forming a "hook" on the ends, about 3". If this is not easy to do and fit, allow at least 100mm lap for capillary action and lay in a line.
Seal the lot with the water proof roof sealer, when finished, sold by wicks, the one that works on damp roofs, cost about £30 a tin about 2.5 ltr. It has chopped up fibreglass etc and seals really well. they also sell it in a skeleton gun tube for sealing a tidy bead.
Any intricate shaping or "dropper" into the gutter hopper can be formed in lead and sealed in. Best to clean the brush in petrol, the stale stuff you should'nt have left in you're lawn mower this winter! White spirit isn't any good! Hope this makes sense. Regards rodders