Concrete outbuildng leak...

[ray316]

l have a outhouse with loo and tool shed and it has a concrete roof, it is leaking and getting worse. What is the best stuff to use on the roof.

Have any folks has the same [roblem what do you use/do.

Best places to get what l need and any cheap methods l could use to seal it from leaking..

 

[PrenticeBoyofDerry]

elastomeric sealant, can be brushed on and sets like rubber.

 

[ray316]

The size of the outbuilding is roughly 16x9 ft and it only leaks in 2 spots. Looking up from inside the outbuilding you can see the crack on one spot that runs the width of the building and the drips from a certain point along the crack, and the other spot is right in the corner and along the width of the edge.

l forgot to mention l scrapped up flaking sealing paint and cleaned.

This was done yestaday morning, then l put some Marley Waterproofing Quick Drying Roof Felt Primer on and a few hours later put on Marley Waterproofing Bitumen Paint MW686432 Black , finished doing this yestaday afternoon about 3.00 after doing all the concrete roof not just the spots leaking, and it said on the tin that it would be dry in 4 hours providing the temp is no lower than 5c. Anyway it was tacky dry by 9.00pm and by 11.00 last night it started raining

Went out this morning and it's still leaking in the same spots .

These cracks where water is still coming through need some good stuff to stop it coming through.

Would like to know best stuff to use as cheap as possible, or other methods to stop the leaks.........

 

[ray316]

elastomeric sealant, can be brushed on and sets like rubber.

Where can l buy this stuff prenticeboyofderry and roughly how much is it..

 

[PrenticeBoyofDerry]

Ronseal/Thompson do one, so builders merchants and maybe the big sheds, unless you look online.
It will cost about £9 a litre but larger tubs will come in cheaper per litre.

 

[ray316]

Ronseal/Thompson do one, so builders merchants and maybe the big sheds, unless you look online.
It will cost about £9 a litre but larger tubs will come in cheaper per litre.

Thanks...Need to get these leaks doing asap, it's like a padding pool in the outhouse.

 

[Deluks]

Considered felting or some form of roof sheeting over it?

 

[ray316]

Considered felting or some form of roof sheeting over it?

What adhesive would l use to lay felt on a concrete roof , could l use shed felt and roof primer what is used as a adhesive to put down lead flashing .. the type thats rolled up and you take a backing paper off to put down

 

[Alastairreid]

exterior ply screwed to the concrete deck 1st then apply the covering of your choice!

 

[Deluks]

Or screw battens to the concrete and add sheeting (corrugated bitumen, fibre cement, profiled plastisol, corry galvanised steel etc)
If your roof is flat, as I suspect, then use diminishing strips instead of straight batten.

The flashing you refer to has a special primer that you apply beforehand, can't see how it would be relevant here though. (don't bother putting it over the cracks)