I'm new to the site and about to start prep for installation of a 7 1/2" x 1/2" engineered pine floor. I plan to staple the flooring down with glue on the end joints. My main level is 720 sq ft and I have another 260 sq ft balcony.

On the main level I have an area where the floor sags. No structural problem. 2x10 doug fir framing and 3/4" plywood subfloor. The subfloor is in marginal shape so I have added an additional layer of 3/4" CDX ontop of the original subfloor.

My plan is to lay 15# felt over the original subfloor where the floor dips and pour floor leveler on that. Then 15# felt over that then the 3/4" CDX.

After doing some research on this site that may not be the best plan.

Any opinions on this?

IMO, that 3/4" CDX underlayment is over kill. 1/2" should do the trick. What I've done in situations like yours is use fiberglass or asphalt roofing shingles. The cheap 3-tab type. Layer them up in a pyramid fashion in the low places, feathering them out as you fill in the valleys. Then lay your 1/2" CDX and screw or staple the snot out of it. If you have a high spot, you can sand on the 1/2" a little to flatten the floor. This works really well.

I'm installing laminated floors in my house. I got my kitchen done no probelms. Started my hallway and the floor slants down hill about 1/2 inch in the three feet. The sub-floor runs in to the addition that was put on my house before I bought it. The question is how can I level my floor so I can install the laminated floor>

Hire a pro to do this part. I'm serious. Some of us do go and perform the prep for DIYers. Since it's a critical component of the overall job, it needs to be done right. And it's commonly the aspect that DIYer's often get wrong.

I would agree on hiring a pro to do the leveling. We also have went in and poured self leveler out for DIYselfers'. The most critical thing about pouring leveler is the mixture. Too little water and you will for sure have a floor that will be cracking up and popping loose. Too little and you will have a mess too. Generally you just want to take a 5 gallon bucket and put four and a half inches of water in it, then and in the self-leveler and mix very well with a drill and mixer. Also you will need to clean the surface and prime it with the recommended primer that that specific company says to use, primer...very very important step. With anything in flooring, prep work is a major part. The product we use is this...http://www.custombuildingproducts.com/P ... rc&lang=en

They sell it at homedepot, its around 24 dollars for a 50lb bag. Never had a problem with it. So if you decide to hire someone at least you will know what they should be doing. Good luck

I took a good hard look at it yesterday and agree that this job will need to be hired out. The lower level, 720 sq ft, is waivy and will need a fair amount of leveling. The second level, 260 sq ft, is better but will still require some work. I have quite a bit of DIY experience but this will be too time consuming and I'm sure that a professional could do a better job.

I know this is a difficult question without seeing the floor but anybody have a ballpark on what kind of cash I'm looking at to level 980 sq ft and install prefinished 7 1/2" x 1/2" engineered?

I just noticed it was ply, we don't use self levelers on ply...only on slabs. So to fix your problem whom ever does will have to see what is causing it. More than likely they will have to pull sheets of ply out and either plane down joists that are bowed or take them out and run a line to make all of them level then scab them back on. Here we charge $125.00 per sheet to take up and put back down. As far as the 2X's go it all depends on what exactly needs to be done. Its not going to be the cheapest thing you have spent on your home i can tell you that. Also you cannot nail through leveling compound, it will crack. You can only glue and lay tile ontop of leveler. And as far as installing the wood that all depends on the normal pricing there. Here i get $4.50 a foot for retail work on wood, tile is $6.00 a foot for straight lay on subfloor, $4 on slab. So really all of it will depend on the pricing in your area, just don't jump on the cheapest one. Check them out on BBB.

Get estimates. It's the only way to know what the going rate is in your area.