Hi

Just finished putting new shed/gym up and done it single skinned block to rears and facebrick on front as in pic.



The fibreglass roof is now on and inside walls have been roughed and plastered.

I layed a membrane on the concrete base and theres a dpc but i have lines of damp inside after heavy rain on the rear walls, you can even make out the blockwork where it has seeped through the moratr joins.

I understand its only single skin but would roughing the outside help with some waterproofer in the mix.

How can i stop or at least help the situation ??

Cheers

yes it will help, but not cure your problem.

One of the reason houses are built with an outer & inner brick skin is becuase bricks are POROUS and you need an air-gap to act as a barrier to stop dampness entering the property.

When water touches the outer surface of the brick (or block), water tension will cause a wicking action which will draw water through the brick until the whole brick is uniformly wet. This action can be easily demonstrated. Get a strip of toilet paper put a few drops of water on one end. You can observe the wicking process in action as the water tension draws the water across the paper.

The same process is why your inner walls are damp. Depending on the temperature difference between the air and water at the inner surface, the water will either evaporate into the air, or condense and run down the wall.

In a normal double skin house, the inner layer of the outer skin will cold enough to let the water condense and run down the wall. Withouth ever reaching the inner brick skin.

The reason you can see darker lines where the mortar joins are, is becuase the mortar is probably more porous than the blocks, drawing more water in. Either way you've only got half a building there.

I'm not a builder so this maybe totally impracticle, but only two possible solutions I can think of... Paint the entire inside of your shed in PVA! to make a waterproof skin. Or build a 2nd outer brick wall to act as the weather skin!

Otherwise I'm afraid your only other option will be to place a barbecue stove in the shed and use it as a Sauna!

_________________
Don't buy a dwarf with learning difficulties,
It's not big and it's not clever.

That won't work. PVA is water soluble - you'll just end up with a sticky mess on the walls. You'd need to use a liquid membrane solution such as Black Jack DPM

Black Jack DPM

_________________
Cheers,
Darren

Property Refurbishment & Maintenance Dorset

That looks good, my option seems to keep water off the wall then. Firstly going to rough it thickly with waterproofer added and leave a nice drip edge. The going to paint it with rubber bitumen.
Then contemplating fixing some treated fence panels 2" off the wall to make it look better and keep water off it.

It was only built on a 'whim' s i had bricks spare and was planning just to put a wooden shed.

Cheers peeps