Is it good - Bondall Bitumen Waterproofing membrane?

[FenceFurniture]

Can't think of another sub-forum where this could go (except maybe Timber).

Does anyone have any feedback about the effectiveness of Bondall Bitumen Waterproofing membrane?

Having recently discovered that the guy building the retaining walls for the vege garden has used H4 timber when H5 is really what is required for timber/soil contact, the owner has decided to take to preventative measures. I found the Bondall product at Masters for a good price ($86 for 20 litres) and so suggested it might be worth a run. I have applied the first coat to some parts today and it certainly looks pretty impressive when it goes on. It will be applied to the back of the posts that face soil, and the back, ends and edges of the sleepers (the front will be painted with SolaGuard).

My next project is to build a wood-storage shed and I'm seriously considering using this bitumen product over the bottom part of the posts that will be in concrete because concrete will wick water through to the post. Dig the hole, ram 100mm blue metal, 100mm of concrete to go off overnight, then concrete the bitumen coated post in, battering up the concrete to let water run away from the post. Run the bitumen about 200mm above the concrete.

[Enfield Guy]

I tend to use the Pabco product. Only because I have had good repeatable results from the product. It is vital that the finished surface has enough thickness to avoid piercing by rock. In tanking applications I usually cover the coating with corflute to protect it. In your case with a garden bed I would give the material 3 good coats, allowing good time between to dry. I would then install and cover with corflute then backfill. Real Estate signs are a great cheap course of corflute.

cheers

[FenceFurniture]

Thanks Bevan. The corflute would have to be pierced or cut to each sleeper to avoid a dam. In this case there'll be a double layer of silt cloth against the wall so that should offer some protection against rocks. I'll be sure to keep them away from the wall when I backfill it.

[DaveTTC]

I used double layer coreflute on a recent job. The stuff was cheap enough (client paid anyway)

Dave TTC
Turning Wood Into Art

[Bushmiller]

Bondall make good products. I use their varnish, but have no knowledge of this bitumen product.

Regards
Paul

[FenceFurniture]

This is the interim report I sent to the owner this morning:

"I started application yesterday and got the back of most of the posts done and one edge and end of all the sleepers. It's very viscous, to the point where a 2x1 stick 3 feet long will just stand up in the drum, but it goes on well (I used a brush rather than a roller).

I had the opportunity this morning to see how it repels water, as it rained overnight. Very well indeed.

I put a thread on the forum looking for feedback from others users of this product. One guy uses Pabco brand and gets good results. He suggested putting corflute sheets on the back of the sleepers to protect them from rocks penetrating the bitumen. However, the corflute would have to be either pierced or cut to size to avoid creating a dam. In any case I think the double layer of silt cloth will afford protection from rocks and stones, particularly if I avoid putting them against the walls when I backfill.

Blue metal against the wall would now be a bad idea for the above reason. However, for consideration, we could put one layer of silt cloth on the wall, then ~50mm layer of coarse sand, next layer of silt cloth and then backfill. To get the layer of sand fairly uniform I could put a 6' sheet of masonite about a foot wide on its edge, fill up to half way (6" up the board), drop sand over the back, pull out the board, rinse and repeat. That would consume about a cube of sand (18 sq.m by 50mm thick is 0.9 m3)."

[Enfield Guy]

Brett
You could also use Terra Firma, or any other Geo textile fabric. Just had another thought, I can't see why 30 or 40mm river stone would not work. I would be disinclined to use sand against the membrane. The idea is to allow free flow of the water in the intended direction. River stone, while more expensive, is smooth and much less likely to pierce the membrane.

Is the silt cloth you speak of the stuff a bit like shade cloth? If so, don't use it in my view. You would be better served with a couple of layers of Geo textile.

Cheers
Bevan

[Enfield Guy]

One really, really important point to remember with tanking, redirecting water. You can coax water to go where you want it to go, you cannot force it, it Will go where IT wants to go at the end of the day.

Boy could I tell you some stories of dudes who didn't understand or appreciate that.

Take care, don't skimp, and it can be done. Less care and skimping on cost will most likely mean a very, very expensive exercise to remediate.

Just sayin'

[DaveTTC]

If it's still an option i would
1) core flute against retainer


2) ag pipe between core flute and bank


3) geo fabric or the like against dirt bank
4) back fill with blue metal (or river stone if you like





Dave TTC
Turning Wood Into Art

[FenceFurniture]

Thanks Bevan. By "silt cloth" I actually meant Geo fabric. The river stone is a very good thought.

[DaveTTC]

Couldnt find my pics of the geo fabric in place

Dave TTC
Turning Wood Into Art

[Enfield Guy]

Good work there by the look of it Dave!!