"We use this on our timber outbuildings once a year. One coat sprayed to saturate the wood. Full water repellency doesn't last a whole year but WaterSeal does maintain the condition of the timber, allowing it to turn a natural grey colour over time, which fits into the countryside far more sympathetically than the usual black/brown/green/orange timber preservatives."
"I bought this product on the basis that it was the original solvent based material that I had previously been pleased with, and the current catalogue clearly shows N and Xn hazards indicating a solvent-based product. But it's not!! It's a thin water based product which is not easily absorbed and just runs off unless the surface is extremely porous and dry.
I took the can back and explained the incorrect description and left with a tin of the No Nonsense equivalent, which is solvent based and others have found to be good.
The Thompsons product may be OK under ideal conditions but I was waterproofing a chimney and need the best result I can get."
"Had an unopened tin of Thomsons water Sealant in garage for about six years and decided to use it on my roof after power cleaning same. Went on nae bother and could see it leaching into the porous tiles. Bought additional tins to finish the job only to find that the Thomsons formula had changed from solvent based to a water based product. This water based product was milky in appearance and did not absorb into the tiles easily. I took my tins back and bought the cheaper No Nonsense range solvent based product which went on a treat. Maybe I'm old fashioned but to me a solvent base is better protection from water/rain than a water based product. I can only think that Thomsons altered their formula because a water based product is "environmentally friendly" and is easier stored and does not carry the same restrictions as a solvent base plus they "talk up" the new product benefits. Its solvent based for me every time !!!"
"I had previously used the spirit based Thompson's Water Seal. It advised 2 - 3 coats. Having done this the bricks were completely waterproof. You could throw a cup of water at it and the water ran off in tiny beads - NOTHING absorbed. Have just used the ONE COAT version (water based) and have thrown a cup of water at it - the water did NOT run off - it was absorbed. Will need to do more coats."
"Used the original spirit based Thompsons for years. We build traditional buildings and our clients like the natural timber finish of featheredge boarding which the original formula allowed us to keep with full water repellence. However the 'improved new formula' in the same tin no less is absolutely useless on timber and I would guess under performs the original in other areas also. Thompsons shouldn't market this stuff in the same tin because it most certainly isn't the same product. Fortunately a large chain DIY store still sells their own brand spirit based product."
"The solvent-based alternative available on the Screwfix website is just so much better and cheaper. This stuff just runs off. Most of what you have paid for ends up on the ground. Yes it is environmentally friendly, it doesn't smell particularly so doesn't give you a headache but it doesn't work either. The choice is yours....."