Hello
I am going to lay a new kitchen floor with water-based underfloor heating and need to level the floor joists.
The problem is essentially in all directions, wrong cc (~75cm), sagging, different heights, and twisted. The joists are substantial (about 120x220).
The two most common alternatives are:
1) screw/glue new joists on either side of the existing joists
2) "Shim" the floor (with materials like masonite, cardboard etc.)
Option 1 is preferable, but the downside is that since some of the joists are twisted, it will be difficult to glue without first planing the sides straight (or alternatively planing the new joists horizontally afterward).
I have then thought of an alternative method that I would like help evaluating.
First, I thought of screwing boards (unfinished wood) on either side of the joists, as in option 1 above. The twisted ones can be fixed vertically with wedges or spacers before screwing. Any gaps can be sealed with some type of flexible sealant.
This essentially creates a mold that should be excellent for self-leveling compound. You apply primer and then just fill until you've reached the edge of the "mold." I would level each joist individually with the compound.
Then it's just a matter of screwing the chipboard into the existing joists through the leveling compound into the existing joists. The "mold" can stay in place to hold everything if the compound cracks.
The mold probably can't be counted as a load-bearing part, so the cc issue remains, but the floor should hold since I actually plan to lay double load-bearing chipboards and eventually choose a load-bearing wood floor on top. The idea is that the floor shouldn't depend on the top floor if we want to change someday, even though it happens to be load-bearing in itself.
I have never used self-leveling compound.
Does it crack easily? Can you screw through it? Is there a more suitable compound/filler? Can the compound absorb moisture (cement-based) and damage the joists?
What do you think?
Would it work?
Sorry for it being so lengthy
I am going to lay a new kitchen floor with water-based underfloor heating and need to level the floor joists.
The problem is essentially in all directions, wrong cc (~75cm), sagging, different heights, and twisted. The joists are substantial (about 120x220).
The two most common alternatives are:
1) screw/glue new joists on either side of the existing joists
2) "Shim" the floor (with materials like masonite, cardboard etc.)
Option 1 is preferable, but the downside is that since some of the joists are twisted, it will be difficult to glue without first planing the sides straight (or alternatively planing the new joists horizontally afterward).
I have then thought of an alternative method that I would like help evaluating.
First, I thought of screwing boards (unfinished wood) on either side of the joists, as in option 1 above. The twisted ones can be fixed vertically with wedges or spacers before screwing. Any gaps can be sealed with some type of flexible sealant.
This essentially creates a mold that should be excellent for self-leveling compound. You apply primer and then just fill until you've reached the edge of the "mold." I would level each joist individually with the compound.
Then it's just a matter of screwing the chipboard into the existing joists through the leveling compound into the existing joists. The "mold" can stay in place to hold everything if the compound cracks.
The mold probably can't be counted as a load-bearing part, so the cc issue remains, but the floor should hold since I actually plan to lay double load-bearing chipboards and eventually choose a load-bearing wood floor on top. The idea is that the floor shouldn't depend on the top floor if we want to change someday, even though it happens to be load-bearing in itself.
I have never used self-leveling compound.
Does it crack easily? Can you screw through it? Is there a more suitable compound/filler? Can the compound absorb moisture (cement-based) and damage the joists?
What do you think?
Would it work?
Sorry for it being so lengthy
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It is useful to think outside the box, but I don't believe in the idea.
1. I think the flytspacklet will crack.
2. The golvspånet should normally be glued to the beams, in your case, you should glue it to the flytspacklet.
And I don't think the flytspacklet will handle the movements well.
1. I think the flytspacklet will crack.
2. The golvspånet should normally be glued to the beams, in your case, you should glue it to the flytspacklet.
And I don't think the flytspacklet will handle the movements well.
Another method is to glue the stud to the beams and plane it down.
So, if it is 2cm low, cut a regular construction stud to 2.5cm.
Screw and glue it in place, set a rotating laser in the gap, and plane down to the line.
Go over the surface with a straight edge.
I mean an electric hand planer.
So, if it is 2cm low, cut a regular construction stud to 2.5cm.
Screw and glue it in place, set a rotating laser in the gap, and plane down to the line.
Go over the surface with a straight edge.
I mean an electric hand planer.
It is also convenient to measure the deviations before starting with the laser to find the highest point. Worth mentioning is that it is easier to split a plank to 1cm and plane it down to 3mm than to try to screw-glue a 3mm thick piece.
It may feel cumbersome, but if you want the flooring chipboards to interact with the floor joists, the shimming must be glued. If you use masonite etc., you might as well skip gluing the chipboard to the joists.
It may feel cumbersome, but if you want the flooring chipboards to interact with the floor joists, the shimming must be glued. If you use masonite etc., you might as well skip gluing the chipboard to the joists.
Thank you so much for your opinions.
Sounds like I should skip the putty.
The choice will probably fall on the electric planer as JOW suggests.
It has been a long time since I took it out for a spin, so that could be fun....even if I'm afraid it will be a bit of work.
The laser I got for Christmas will also be used
I hope that most of the studs are straight enough so it works to screw-glue new beams on each side.
I will also need to short-circuit, but I would rather avoid it across the entire floor, but it's a good thought nonetheless.
Sounds like I should skip the putty.
The choice will probably fall on the electric planer as JOW suggests.
It has been a long time since I took it out for a spin, so that could be fun....even if I'm afraid it will be a bit of work.
The laser I got for Christmas will also be used
I hope that most of the studs are straight enough so it works to screw-glue new beams on each side.
I will also need to short-circuit, but I would rather avoid it across the entire floor, but it's a good thought nonetheless.