Weatherproofing blockwork garage

philbostavros

Hi

We've recently had my son's detached garage rebuilt - it's at the bottom of his garden and was very delapidated.

To keep costs down, it was built on the original footprint, in single skin blockwork, with a pitched tiled roof. With the recent very heavy rains, there seems to be a lot of dampness penetrating the blockwork, more so than the old brick construction (no sign of any leaks though).

We intend kitting out as a combination workshop/office and will take the necessary steps to damp-proof the interior (whilst again keeping costs down as much as possible). I would welcome any advice on the best way to protect the outside of the blockwork.

I have thought about simply using a good exterior emulsion or other sealer or possibly cladding the walls e.g. upvc (though this would work out more expensive - even fitting myself). It's approx 5m x 3.5m and would only need to do one long wall and the 2 end walls (the garden-facing side wall has been rendered).

Cheers for any experience/advice.

iamcornholio

Blocks are going to be very porous as they have lots of voids in them. So I don't think a coating of paint or a waterproofer would be much use.

The only sure way would a a physical external barrier such as render or cladding

Or polythene on the inside, then batten and line with plasterboard or ply, and cut some weep holes at the bottom of the block wall to drain any moisture out

If you want to try exterior waterproofing, then look for a silane based product, and not the common silicone one like Thompsons

Also make sure that the roof eaves are not letting water pour down the wall

SailorSam

We built are garage with concrete 'breeze blocks' and had a cement render, can't say i've ever noticed any damp. The base of the walls were done in ordinary brick then a plastic Dpc before the blocks.
If you want to use it as an office i think i'd be putting battens inside to attach plasterboard to, perhaps squeeze in some insulation.

karl-123

get hold of a 25 litre drum of damp injection fluid

about £ 36 from hss

and spray/brush that on,

http://www.ebay.co.uk/itm/DPC-injection-fluid-water-based-20l-/180757913583?_trksid=p5197.m7&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D2%26po%3DLVI%26ps%3D63%26clkid%3D4883051380009101015

iamcornholio

karl-123 wrote: »

get hold of a 25 litre drum of damp injection fluid

Will that be UV stable and last more than a year in this use?

philbostavros

Thanks folks.

I plan to take suitable measures with kitting out the interior and wanted some suggestions as to how to try and limit moisture/damp from the outside first.

I know that cladding will be most effective but more costly and take longer, so will look at all suggestions that people offer.

Cheers
Phil

bradleigh1977

There is a product you can buy, if you don't want it clad/renedered. Its a water repellent, and you paint it on. It not like a water seal, and blocks it, allowing it NOT to breathe, this stuff alows the brick/block/stone to breathe. Its called dry seal...its not cheap..but works...this is the company i use, down i devon

http://www.dampness-info.co.uk/damp%20shop.htm#Bondacryl

But id get it rendered first.