Long-lasting waterproofing for brickwork?

itm2

We've had an ongoing problem with leaks due to our brickwork becoming saturated during periods of heavy rainfall. We had the problem resolved about 10 years ago by having the main wall painted with some sort of waterproofing solution.
The waterproofing now seems to have worn off (we've started getting the same leaks again) so we were thinking of doing the waterproofing ourselves as there's only one wall to be done.
Can anyone recommend a solution/coating which will last a few years? I've been looking at Screwfixes's "NO NONSENSE WATER REPELLENT SEAL", which seems to be the right sort of thing, but I've read some feedback which suggests that it only lasts for a couple of years.
Can anyone recommend something which is likely to last for a 3-5 years at least?

Furts

Why, or how, is your wall becoming saturated? This needs thought, and ideally sorting, before you think about painting on sealers.

FreeBear

Furts wrote: »

Why, or how, is your wall becoming saturated? This needs thought, and ideally sorting, before you think about painting on sealers.

Agreed. Blocked gutters, downpipes, and/or ineffective soakaways would be the first suspects. If the walls are getting saturated at floor level, then look outside to see if the DPC has been bridged. Consider installing a french drain if the external ground level is below the DPC.

Sealing the brickwork will trap moisture in the walls, and come the winter, the water will freeze causing the bricks to spall. That said, with the warm weather we've had for the last couple of weeks, the bricks will have dried out a little. Although a rule of thumb says walls need one month per inch to dry fully.

Modern cavity walls by design, shouldn't suffer from internal damp if the outer leaf gets soaking wet - if the damp is penetrating, then there are other problems that need resolving.

itm2

The wall in question is one level up - in the middle section of a 1970s 3-storey townhouse. We have an extension at the rear, with a flat roof terrace on top. The wall in question is part of the original rear wall, and runs from the roof terrace to the roof tiling on the upper floor of the house.
I had a number of builders and surveyors look at it over the years, each offering different but speculative theories. We've had the roof re-asphalted and paved, gutters and drains checked and cleared. The only thing to stop the leaks has been the waterproof coating. Hence the original question.
Be grateful for any recommendations for an appropriate sealant, even if it's not an ideal fix, as we've spent years searching unsuccessfully for the root cause.

bobbymotors

Stormguard

Its very expensive, but very good

itm2

bobbymotors wrote: »

Stormguard

Its very expensive, but very good

Is Stormguard intended for use on brick walls? It looks like the sort of thing you'd use to seal smaller surfaces.

bobbymotors

itm2 wrote: »

Is Stormguard intended for use on brick walls? It looks like the sort of thing you'd use to seal smaller surfaces.

sorry....STORMDRY

my bad

it's good stuff

itm2

bobbymotors wrote: »

sorry....STORMDRY

my bad

it's good stuff

Wow - £120 for a 5L can. About 6x pricier than the Screwfix stuff I was looking at. If it's genuinely good for 25 years then it would indeed be worth it, but at that price it would be a bit of a gamble!