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1950 Subfloor help

mwood2278's Avatar

Join Date: May 2013
Posts: 11

05-14-13, 08:14 PM   #1  
1950 Subfloor help

Our living room has original hardwood floors on top of the original sub floor(as seen in the photo). We would like to continue the transition into the kitchen but we can see the crawl space between the between the planks in the subfloor and are apprehensive of putting hardwood floors down on it. Also when we walk on the old subfloor it's a little springy.

If we put OSB down in our kitchen the transition will be 1/2 inch higher to the living room. Should we just give up and put the new hardwood floor with a vapor barrier down on the original sub floor?


Last edited by mwood2278; 05-14-13 at 08:38 PM.
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chandler's Avatar
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05-15-13, 02:57 AM   #2  
Looking at the pix, I would consider laying subflooring panels on the planks, as the planks do not offer good substrate for hardwoods. If you have a transition, then it just has to be.

Pulpo's Avatar
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05-15-13, 02:31 PM   #3  
Secure the planks first, if needed.

Nashkat1's Avatar

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05-15-13, 08:17 PM   #4  
I would secure the subflooring anywhere it needed it with some coated sinkers or ring-shank nails. Then I would lay rosin paper and install the hardwood directly to the subflooring. Good T&G hardwood flooring properly kicked into place and nailed with true flooring nails driven through the upper edge of the tongue will practically support itself.

Underneath, I would cover the dirt with a layer of plastic, make sure the space is well-ventilated, and insulate the supply pipes.

marlin300's Avatar

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05-29-13, 09:03 AM   #5  
don't use OSB on sub flooring, it has no structural strength, if your sub-floor is spongy replace it with either 5/8 or 3/4 plywood havent seen the picture you posted here but if it is tongue and groove, chances are it is 3/4

chandler's Avatar
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05-29-13, 01:23 PM   #6  
Most subflooring available today is OSB (Advantech for instance), so I fail to see where we should warn others not to use a product that is used every day for that purpose. It is also used every day as exterior sheathing on houses specifically to give it structural stability. Just curious as to your warning.

Gary in WA's Avatar

Join Date: Mar 2013
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05-30-13, 07:59 PM   #7  
NO red rosin paper, from the manufacturer, "Blue" pp.9;

"The 2006 International Residential Code
requires a vapor retarder on the warm-in-winter side of exterior floors (a floor over a
vented crawl space, for example), with a vapor permeance of 1 perm or less in Zones 5
and higher.
3. Over a wood subfloor, do not use an impermeable vapor retarder material with a perm
rating of .7 or less, such as 6 mil polyethylene film or other polymer materials, as it may
trap moisture on or in the wood subfloor.
4. Do not use common red rosin or building paper which is not asphalt saturated. They are not vapor retarders as their perm rating is far greater than 50." Closer to 100.

I suggest "Aquabar B" at 0.87 perms; http://www.fortifiber.com/pdf/data_s..._aquabar_b.pdf

Red rosin paper would not meet either of these requirements.

Install over existing solid wood subfloor, pp.37. Use structurally rated/thickness OSB, pp. 15 (blue at left side). https://docs.google.com/viewer?a=v&q...2R_E90aeJSkd7Q


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