Browse Forums Paving & Concreting 1 Sep 12, 2013 2:00 pm Hi guys, hoping I am posting this in the right section (was tossing up between concreting, landscaping and pools section). I am looking for some advice on how to firstly lay a slab for the base of a pond. The top of the pond is level with the ground and is 500mm deep. Dimensions are about 5m long, 850mm wide and 500mm deep. The laying of the slab itself is pretty straight forward, about 100mm think, wire mesh etc. the issue I have is how to “tie” the slab to the 3 existing walls which are actually foundations to the house – see pic. I am concerned that over time the slab may move independently from the 3 other walls ie: the rest of the house(the fourth wall on the right hand side of the pic will be new blockwork which will also be the retaining wall ontop of the new slab). I was going to pour the slab right up against the existing brick work, render and water proof the brick walls to form the sides. I guess the first question is would the slab be expected to move independently from the house over time? If it does I have concerns that small gaps will open up and cause leaks. What options do I have? Can I somehow “tie” the slab to the existing 3 walls so that if it does move they all move in unison? Is this something I need to be concerned about? The only other thing I can think of doing is to build 4 walls instead of just the 1 retaining all on top of the slab. That way if the slab moves all sides move equally and in no way tie it to the house itself. I really wanted to avoid this if at all possible but if its my ONLY option then so be it. All comments and suggestions welcome! Thanks heaps. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Concrete pond advice 2Sep 13, 2013 6:41 am Would build independently to house, will be trouble down the track for sure. Be also mindful of any termite protection breached Landscape Design & Construction http://cherub.squarespace.com/ Re: Concrete pond advice 4Sep 13, 2013 10:00 am keen I don't quite understand your build. Are you looking to make the walls of your house the walls of the pond ie water against your house? Spot on - that was what we were hoping as the walls are already there and we can get the water right up close to the house for effect, with waterline being 100mm or so below the house floor height. Obviously they will be rendered/waterproofed but i have concerns about movement opening up cracks. Re: Concrete pond advice 5Sep 13, 2013 11:55 am The only way I could see this working is if it was designed into the house in the first place. As a retrofit it is a nightmare. All I can think of is a monolithic concrete structure inside the space or a pond liner of some sort. Ask Cherub or onc_artisan. Re: Concrete pond advice 6Sep 13, 2013 12:09 pm Yes i am beginning to realize that it may be a challenge. I was considering using something like the liquid rubber membranes that can be painted on nice and think. By the looks of them they are very flexible and may withstand movement without rupturing. Are Cherub or onc_artisan frequent visitors to this forum? Thanks for the tips. Re: Concrete pond advice 8Sep 13, 2013 3:13 pm Where you are coming from is where you are going to... Yes, unless you are in a low intensity rainfall area or the area is protected from rain. Do you have access to NCC Part 2 or can you download it? I can email you a copy… 10 12512 Versaloc is a mortarless besser block system that still needs a properly engineered footing. If you just do a 400x200 footing it will fail in time. At 17m long you need it… 1 17808 |