I don't think underfloor heating will be as effective if you have the pipes and plates under the chipboard. If you're going to have parquet flooring, you can space directly on the floor joists, lay the pipes and plates, and then the parquet floor. I've done it a few times and it turns out very well. Better and cheaper than grooved chipboard flooring.
Thank you for the very helpful answer, Dr Trä, I still have a few follow-up questions:Dr Trä said:I would not recommend using asfaboard in the subfloor, it usually sags over time. Oil-hardened 9mm masonite is typically used for subflooring. It is very stiff and comes pre-cut to width for 60cm centers.
If you're worried about flex, you can "cross brace" the floor. This involves putting a cross of something like 45x45 in the middle of each bay. Alternatively, you can notch in a regular beam which is easier but maybe not quite as good. This will make the floor more stable.
Tiles shouldn't be a problem, but I would do things a bit differently. I would skip the battens and plates, and lay the hose directly on the chipboard and then screed the floor with reinforcement. The right thickness of screed is important to avoid cracking.
But if you have the opportunity to add a support beam in the middle, it's probably not a bad idea
I don't think the underfloor heating will be as effective if you have the hoses and plates under the chipboard. If you're going to have parquet flooring, you can batten directly on the floor joists, lay the hose and plates, and then the parquet. I've done it a few times and it turns out very well. Better and cheaper than grooved chipboard.
You don't recommend asfaboard but instead oil-hardened 9mm masonite. I can't find any 9mm but I did find 6.4mm at Beijer
http://www.beijerbygg.se/store/priv...kivor/board/oljehärdad-board-1220x2440-2-98m2
However, it costs 151:- per m2
In that case, I'd probably rather buy the Buildingmax subfloor board for 90:- m2
http://www.byggmax.se/skivmaterial/byggskivor/plywood-och-osb/trossbottenskiva-p07040
But how does my reasoning about raw timber boards stand; can I use it? Is there any downside other than it's a lot of work? If I go with cc450, it will still be a lot of work with prefabricated boards and a lot of waste.
I read up on cross bracing, didn't find any obvious advantage over blocking other than potentially preventing drafts. I'll probably use blocking, seems easier to nail together and also easier to insulate if using insulation boards.
Regarding the tiles, you make a good point by skipping the battens and instead screeding the hose directly on the chipboard, sounds a bit expensive but on the other hand, you save on the plates which is quite costly.
But the hose I'm using is 20mm, which means a lot of screed over, say, 70m2.
Maybe I could cut drywall and lay it between the hoses so they end up on cc300 as they should be to reduce the amount of screed? The screed is supposed to cover the hoses by about 3 cm if I understand correctly, so 70m2 x 5 cm = 3.5 m3 of screed, looking at Buildingmax, you need 6125 kg of screed costing 46305:- sounds a bit expensive
I have done as you describe with parquet, laying it directly on the battens in a room upstairs; it works but creaks a little, I think, although the cc dimension was maybe 1000, but the battens were about 35mm.
In the room where there will be wood flooring, it might still be the smartest option.
Best regards
If you space them at cc 30 and place beams at two locations, a c24 220x45 will suffice for 4.5 meters. If you want to have tiles with underfloor heating, I would go with grooved, glued chipboards with about 20mm reinforced self-leveling compound on top. Cc 45 makes it harder to lay floorboards if you want a joint on the beam. There are good waxed hardboard sheets for the subfloor. You can also screw foam boards under the joists, which is said to be advantageous. But opinions may vary on that. It's also important to ensure you have access.
I looked a bit at the oil-hardened masonite and it seems to only be available in 6 mm now. It was a couple of years ago that I used it, and it seems to have been phased out or something. 6 mm should be fine as well. Raw planking feels like a huge job and it won't be as airtight either. Since the raw planking dries apart. Blindbottenbräda as you intended and masonite is my recommendation.
Yes, a lot of self-leveling compound is needed. At least 15 mm should be laid above the top of the pipe, preferably 20 mm above, I've heard. So reinforcement on the chipboard, pipe, and self-leveling compound will be around 45 mm. Do you have any heights to follow? The gypsum strips might be a problem when you need to have a reinforcement grid, possibly if you place the grid above the pipe. Check that with a tile setter. This method is, in my opinion, clearly the best if you're going to have tiles and underfloor heating in wooden joists. Check the price of ordering a truck with self-leveling compound; it will be too much to mix everything by bag.
Ok, you mention creaking with a sparse floor. I haven't noticed that, but then again I had cc 60. Did you screw or nail the sparse flooring? How did you handle the turns with the underfloor heating?
Yes, a lot of self-leveling compound is needed. At least 15 mm should be laid above the top of the pipe, preferably 20 mm above, I've heard. So reinforcement on the chipboard, pipe, and self-leveling compound will be around 45 mm. Do you have any heights to follow? The gypsum strips might be a problem when you need to have a reinforcement grid, possibly if you place the grid above the pipe. Check that with a tile setter. This method is, in my opinion, clearly the best if you're going to have tiles and underfloor heating in wooden joists. Check the price of ordering a truck with self-leveling compound; it will be too much to mix everything by bag.
Ok, you mention creaking with a sparse floor. I haven't noticed that, but then again I had cc 60. Did you screw or nail the sparse flooring? How did you handle the turns with the underfloor heating?
Katos, I have a small question for you. Were you planning to putty on the sheets then? Or lay a board and putty on that? Hmm, it doesn't sound so good to have the underfloor heating so far down. The thing is that the hose should be in the self-leveling compound to get good heat distribution and a more solid floor.
I don't quite understand what you mean. Of course, you apply filler on the plates with 20mm leveling compound. The system is designed for that. 45mm leveling compound sounds like a more expensive construction. Gluing drywall is also an option if you can't achieve cc30 and need more stability, but in this case, it feels unnecessary. I've done it a couple of times myself. But overall it seems more straightforward to use a tested and dimensioned system. No need to reinvent the wheel every time.
Okay, I have called LK floor heating. Their response was that you absolutely must not apply leveling compound on the plates, as there is ammonia in the leveling compound that corrodes the plates. If you still want to use this system, you should place a plastic sheet or board on the plates and then apply the leveling compound. 30cc was a requirement they had for this system. However, he also said that the other option with regular chipboard, reinforcement, tubing, and leveling compound was preferable.
can't you install sparse paneling with tubing and plates, then screw on 1 or 2 layers of floor gypsum and then tiles directly on the gypsum?