floor leveling masonry substitutes? 1/2 inch subfloors for bamboo floors?


Hi, we are new homeowners to a 1890s house, wanting to put bamboo floors in (which we already purchased by getting a great deal for under $2 a square). We have jacked up the house with beams to straighten the floors to the best, but still have some spots that are 1- 1 1/2 inch off level. We have blown through a 120hours labor and $700 worth of floor leveling material ($29/50lbsbag), and only have completed about one quarter of what needs to be done. It seems like if I use masonary cement mix it would allow for longer dry time thus longer pour time thus equaling more productivity. i am frustrated with every carpenter's opinion, their solutions seem to add up to thousands of dollars. I was trying to bring the floor to at least an 1/8 inch over a 4ft plane, and then use 1/2 inch ply because I have a bundle on site. I know the 1/2 inch is below spec of 3/4, is it really worth buying the 3/4?
So is there any other product to level out the floors? If they floors were 16 on center, it sounds like ripping them down to the beams would have been the best way to go. But that's not an option at this point, as we are already too far into the floor leveler project, as I am already 1/3 done with downstairs. Will Gypcret or some other part floor leveler/ cement mix work? should i glue or nail the floors or drill and screw the subfloors down? Any information is much appreciated!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
one issue with the gypcrete, or any cement based materials is that they need to be a minimum thickness over wood subfloors, because the material is fairly brittle, and the wood floors flex a bit. I believe the minimum is about 1.5" so quite a bit of modification is needed for the change in height.
bill

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

it seems that even the original floor levelers are also quite a bit brittle? it seems like adding foam to masonary (such as small packing pellets) would be ideal for flexibility, weight and cost? wouldn't metal lath prevent cracking? if it cracked, does that matter if it's under the sub floor? even the floor leveler, where it is below a 1/4'', has cracked in specific spots already... thank you for your input!!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
If you're getting cracking with Ardex type products, it probably indicates the the subfloor is not rigid enough. Rigidity is improved with the thickness of plywood, possibly screw and glue the plywood. Another big factor often overlooked is the condition of joist bridging. This is the structure between joists, sometimes full blocking, sometimes cross-bracing. If the subfloor is stripped off all the way to the joists, there are metal bridging products. The idea is that if a joist tries to move, it must move the adjacent joists as well, making the entire floor much firmer.
Bill

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Your floor doesn't need to be level only flat (you could install it on a ramp). Your flooring should have the specs as to how flat it needs to be.
1/2" is no good by itself, you may be able to get by if you doubled the 1/2" but that is a question for an architect or Georgia Pacific. If you are putting the 1/2" on top of another subfloor that should be fine. Again your flooring should have deflection specs for your subflooring.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Hi, unfortunately Georgia Pacific does not make any masonary products anymore for the past three years, gypcrete cement etc got sold out. the type of cracks i am receivign are expansion cracks, from the expansion of the wood where the crete is under 1/8 thin. it is funny that it doesn't crack or move when applied over linoleum surface, only tung and groove (old) wood. it's true that it doesn't have to be level, only flat but being flat includes getting rid of some of the waves that are over an inch low. questions i am left with: foam in masonary mix anybody? cement mix instead of floor leveler? anybody know the composition of floor leveler?
what about 1/2 inch subfloor under bamboo--i am afraid two inch nails would crack any masonary product, which may still be ok, but the dust created may not? i already have the necessary 1/2'' plywood..
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Why are you trying to raise a wood floor 1 1/2 inches with a floor filler. If there is no way that the old floor can be brought closer to level, why not add various thicknesses of plywood on tapered slats to bring it up closer. Then the floor filler can level the variations between the original floor and the various plywood pieces that are building up the floor close to level. The plus side is that the plywood would add structural strength to the floor. Fasten everything with screws set close together.
I just finished levelling a bedroom floor where part of the floor is in the old house and part is in an addition added 20 years ago. The old foundation is under the joint, part of the old floor had settled and shrunk causing a hump over the old foundation. It was not great but more than the engineered hardwood flooring, I wanted to install, could bend over. I did not want to add 1/2" of floor leveller so I screwed and glued some older 5/16" plywood over the deepest area and then filled over it all to create a flat and level area. Worked great. It is all topped by some 1/4" firply glued and stapled down to make a smooth, nailable subfloor.
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Right on, that's the exact approach we just started doing this afternoon--i used 1/2'' and 1/4'' ply to bring the floor up, put metal lath nailed with galvanized nails over it, and poured a mix of one part floor leveler, one part concrete type 1 2, to 3 parts sand. i poured pea stones in other low spots and feathered it in with a broom and stick, so they were level over the metal lath. we coudl work with it for roughly an hour v. 20min for the floor leveler. we got a lot of square footage done, working three guys, for three hours. two mixing, one leveling. i tomorrow we will see the hardness screw test, hammer test, jump test! i just winged it on the mix, it applied easily, and sure was much cheaper than pure floor leveler. i think the lath will help the crete with its bonding, and the floor leveler should help somewhat with flexibility and flow.
i am planning to drill through the ply and masonary and screw and glue down with low VOC glue--any recommendations??
after the ply is down, i am thinking just to glue the bamboo floor down to the 1/2'' ply, so i dont' have to worry about nails chipping the crete. i have two inch nails, i am afraid they will start chipping and cracking any masonary, yet i will not be able to use a felt vapor barrier. any suggestions on glue? environmentally friendly ones that work well? the masonary looks so good we might put concrete kitchen & entrance floors in--i haven't bought tiles yet! concrete looks like the move as far as my budget goes! my wife says we should consider the fact that concrete kitchen floors may be a bit cold in the winter (which wouldn't matter for the entrance), but she likes the idea. thank you so much everbody for your input!! jason
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.