Concrete garden shed leaking roof

whodafunk

Hi All,

I have a concrete shed with steel roof. I have areas of leaks on one side which backs onto neighbours wall at back. The shed came with the house and serves the purpose - I would just like to tidy up around the area around near where the roof starts (pics attached) and fix the leaks also.
This is completely new to me - I’ve not tried this before.

Thank you

whodafunk

whodafunk wrote: »

Hi All,

I have a concrete shed with steel roof. I have areas of leaks on one side which backs onto neighbours wall at back. The shed came with the house and serves the purpose - I would just like to tidy up around the area around near where the roof starts (pics attached) and fix the leaks also.
This is completely new to me - I’ve not tried this before.

Thank you

Adding pics

GreeBo

Can you share pictures of the outside view of where the leaks are?
Its not clear (to me!) if the shed is free standing or against a wall etc.
Your second pic appears to show daylight visible around the peaks of the sheeting, is this correct or just a trick of the light?

whodafunk

GreeBo wrote: »

Can you share pictures of the outside view of where the leaks are?
Its not clear (to me!) if the shed is free standing or against a wall etc.
Your second pic appears to show daylight visible around the peaks of the sheeting, is this correct or just a trick of the light?

Thanks for the reply. It’s most likely the light in the picture as I took them last night. The leak is at shed wall which backs on to a neighbours garden. You can see from the additional pictures the stretch where the issue is likely to be. Thanks

Calahonda52

Looks like there was never any flashing added when the roof was done, due to the proximity of the overhang.
You can check this by shoving a piece of wire out from the inside and see does it pop up?

jack of all

As Calahonda52 says- no flashing. To do that right you'd need to remove the coping (like like insitu cast) fit foam profile filler strips along the top edge of the sheet and fit a pressed metal flashing over. and redo the coping Pitch looks very low so even with a profile filler there may still be a risk of some water blowback in heavy driving rain conditions.

https://oconnorroofing.ie/product/corrugated-foamfiller/#:~:text=STOP%20SLIDESHOW-,Corrugated%20Foam%20Filler,type%20of%20sheeting%20we%20supply.

Calahonda52

Interesting stuff there J oF A..:)
So, building on that, and knowing it's not a RR job, another idea.
get some of that profile and fix it m maybe 6" out form the wall, on top, ie outside.

Then get some gaffer tape and stick it all the way along inside the foam to cover the C-Iron
Then make up a nice stiff plaster liked mix, not too much cement in it as the C-iron expands and contracts, and level it up all the way along, filling the gap by the wall, the gaffer tape will stop the concrete sticking to the C-iron.

When it has cured and dried out, then cover it and the foam with a good quality flash band like product such as Foil Tack Band Butyl tape from National Seals, bring it up under the coping.
You just measure the width you need and call them up, they will cut it, its in 5m length.
lifetime job, have used it for years

This idea will negate the need to remove the coping which nmight cause some angst with neighbours.
I personally would not touch it, too much risk

the_pen_turner

i would get an L shaped bit of flashing bent. say 200,, by 50 mm(what ever will fit under the cap), then screw it on with stitchers, use foam fillers and put them on with silicone to give extra seal against the sheeting. silicone the short bent up piece against the wall as well.

whodafunk

Thanks guys for all the replies. So to reply to an earlier question I can see daylight through where the water is coming in. Flashing missing like you say. Pics attached from this afternoon during daylight.

the_pen_turner

flashing is your issue. they made no atempt to stop the water blowing back in

whodafunk

Thanks for all the replies. How easy/hard would it be to tackle this job myself?

Also there are largish gaps where the walls meet in the shed (I'll upload some pics now) - what would be the best way of sealing them up?

Could I buy something like Evo-Stick flashband and screw with stitchers as described above into the blocks above the shed roof to allow the water to run off it? Thanks

whodafunk

Picture to show gaps where the walls meet in shed. Would foam filler do the job?

GreeBo

I'd buy a roll of flashband for the top and apply yourself. You want a single piece for the top, no joints.
The wider the better but more expensive, probably 150mm to handle the corrugated finish. Use a seam roller to mould the band to shape. It's more important to get it stuck at the edges than in the middle, but take your time and work in small lengths, the band will flex to fit the valleys of you work it in.

For the other gaps I would just use s sand and cement mix and trowel it in. You could also use exterior expanding foam since it looks like those gaps only let in blown water.

whodafunk

GreeBo wrote: »

I'd buy a roll of flashband for the top and apply yourself. You want a single piece for the top, no joints.
The wider the better but more expensive, probably 150mm to handle the corrugated finish. Use a seam roller to mould the band to shape. It's more important to get it stuck at the edges than in the middle, but take your time and work in small lengths, the band will flex to fit the valleys of you work it in.

For the other gaps I would just use s sand and cement mix and trowel it in. You could also use exterior expanding foam since it looks like those gaps only let in blown water.

Thanks for the reply. How should I attach the flashband to the concrete slabs above the shed? Or should I run it just under the slabs at an angle to force the rainwater to run on to the roof?

whodafunk

whodafunk wrote: »

Thanks for the reply. How should I attach the flashband to the concrete slabs above the shed? Or should I run it just under the slabs at an angle to force the rainwater to run on to the roof?

Pic of top of shed

GreeBo

whodafunk wrote: »

Thanks for the reply. How should I attach the flashband to the concrete slabs above the shed? Or should I run it just under the slabs at an angle to force the rainwater to run on to the roof?

I'd just go from the top of the concrete to the corrugated roof, it might be hard to get a good bond to the hidden slab.
You could use two strips of banding, one between the roof and under the slab and then another from above the slab onto the first band. (Just do the bottom band first)