I am going to build a bathroom upstairs and plan to cast with EPS cement between the beams. On top, we will screed in waterborne underfloor heating.
The casting will be about 100mm, and since the beams are 220mm, a blind bottom is needed (the beams are 300mm on center). The idea is to lay plywood or 22 flooring chipboard on battens screwed into the beams. My question is what dimension the battens need to be. What would be best, diagonal paneling 28x70 or regular 45x45?
An alternative to the above solution would be to fill up with foam. Downwards, there is diagonal paneling 300mm on center that is well-nailed, and you could also spray foam the polystyrene.
Any ideas?
The casting will be about 100mm, and since the beams are 220mm, a blind bottom is needed (the beams are 300mm on center). The idea is to lay plywood or 22 flooring chipboard on battens screwed into the beams. My question is what dimension the battens need to be. What would be best, diagonal paneling 28x70 or regular 45x45?
An alternative to the above solution would be to fill up with foam. Downwards, there is diagonal paneling 300mm on center that is well-nailed, and you could also spray foam the polystyrene.
Any ideas?
I added drywall and joists to get cc30 and placed the floor chipboard so it was level with the top of the beams, and then I self-leveled the floor with 12mm heating pipes... according to Maxit, I should have a minimum of 15 mm self-leveling compound above the pipes for proper load-bearing...
First of all, you want the chipboard floor in a single unit to make it as durable as possible; otherwise, you risk the leveling compound cracking and the waterproofing with it. I would have cut down the floor joists, say 30-35 mm, and glued and screwed on a new beam next to the floor joist, for example, a 45x145, which I then laid the chipboard on and primer + screed to reduce the construction height. I believe that those of you who have cast/framed between the floor joists do not get a rigid floor and risk damaging the waterproofing with moisture damage as a result. So my advice is to either cut down the joists and add next to the joists or accept the construction height. I hope you understand what I mean, otherwise feel free to ask. Putte1: your idea is smart, but I am skeptical about having so many joints in the chipboard floor; it creates many breaking points in the floor.
what do you mean here.. according to maxit that I use, must cast 15mm over the pipes no matter how I solve the floor chipboard.hempa111 said:
Yes, it's the breakpoints that made me think again.. but the carpenters I've talked to didn't think it would be a problem considering that I reinforced with cross-supports at about cc300.
My floor was built in '64 and has never been over cc 500 between the main floor and the old floor was built in the same way but with planks and no cross-supports.
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I was talking about your first post where you mentioned a casting between the beams, the one you now refer to is a spackling; I separate the concepts to avoid misunderstandings. And regarding what Maxit said, you must putty so you have a minimum 15mm cover on the hose, that is correct. Furthermore, I fully understand that you want to minimize the building height because you don't want a step into the bathroom. After our discussion, I have consulted with some of my other colleagues, and they have used the method of bracing and placing the chipboard in between with good results, so if you use a fiber-reinforced putty, it should work well. If you want to feel extra secure, there are special reinforcement mats for the purpose, which I also recommend you use. I hope you have gained some clarity from my answer.