I am going to build a low (60cm) retaining wall with Benders Megawall Garden. The manufacturer prescribes 15cm 8-16 directly behind the wall, followed by crushed rock 0-32.
Since I have 2.5 tons of crushed rock on the trailer right now, it would be more convenient not to use 8-16 and instead use Isodrän/Pordrän boards.
I talked to Benders about this and received positive but somewhat vague answers ("we haven't tested it"). My understanding is that 8-16 only functions to channel any water behind the wall.
I believe this is not particularly uncommon, but I'm wondering if anyone has actually tested it? I only need a couple of square meters, so if I can find a few loose boards that are leftover, it would also be a cheap solution.
Since I have 2.5 tons of crushed rock on the trailer right now, it would be more convenient not to use 8-16 and instead use Isodrän/Pordrän boards.
I talked to Benders about this and received positive but somewhat vague answers ("we haven't tested it"). My understanding is that 8-16 only functions to channel any water behind the wall.
I believe this is not particularly uncommon, but I'm wondering if anyone has actually tested it? I only need a couple of square meters, so if I can find a few loose boards that are leftover, it would also be a cheap solution.
It's probably the combination of drainage and creating a space where frost heave cannot occur that you want to achieve with 8-16, so why not.
In municipal projects with rock gardens and granite, I have seen that some form of isodrän has been used, probably for similar reasons. Keep in mind that a little geotextile is good to prevent organic material from mixing with water and flowing in.
In municipal projects with rock gardens and granite, I have seen that some form of isodrän has been used, probably for similar reasons. Keep in mind that a little geotextile is good to prevent organic material from mixing with water and flowing in.
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Yes, stopping frost heave is of course a function as well, and I think an isodrän board should handle it in a similar way. Geotextile may certainly be needed between the insulation board and 0-32 so that the fine fraction does not clog the isodrän board, on the other hand, nothing like that is prescribed between 0-32 and 8-16.
Last year's wall was built without Isodrän boards, but now it's time for an 8-9m retaining wall again, and I'm pondering this issue with Isodrän once more.
To gain clarity on the original question, I called Isodrän, who clearly stated that the draining layer closest to the wall (8x16) can be replaced with an Isodrän board. The behind-layer of crushed rock cannot be replaced because you want compacted material behind the wall. If you don't fill with material that can be compacted (and compact it), it will press the wall out when the material settles.
So, this time I thought I might avoid fetching a fraction and buy some Isodrän on blocket.
To gain clarity on the original question, I called Isodrän, who clearly stated that the draining layer closest to the wall (8x16) can be replaced with an Isodrän board. The behind-layer of crushed rock cannot be replaced because you want compacted material behind the wall. If you don't fill with material that can be compacted (and compact it), it will press the wall out when the material settles.
So, this time I thought I might avoid fetching a fraction and buy some Isodrän on blocket.