I have two rooms, seperated by a wall with an archway in the middle, that i am hardwooding. The problem is, under the archway is the main beam which has sagged a little but over time (house is from 1930) so right now, from outside wall of one of the rooms to under this archway the floor "looses" 3/4 of an inch over 11 feet and then gains this 3/4 of an inch back over 11 feet again when you hit the outer wall of the other room. So if you were to level a string from the one room's outer wall (thru the archway) to the other room's outer wall the outside floor edges would be level but the floor would droop 3/4 of an inch directly in the middle. ( i hope i explained this well).

The other problem is the floor droops the same way in the middle the width side of both rooms(like parrell to the archway that seperates them)-but that is over about 10 feet and only 1/2 of an inch.

Is this acceptable for installation? The wood floor that was previously on it did not look or feel like it was not level but that was an old 5/16 face nailed oak floor. I am using 3/4 oak solid. What are my options? Will the wood conform enough to not be noticeable? Thanks for the help!

Nick

Alright, do us a favor. Get something that is 6' to 8' long and straight to us as a straight edge. Lay that down on the floor centered between the two rooms and measure the gap underneath.

Heres what I did-I leveled a laser level on one side of the wall so the laser hit the wall of the other room. Then I measured from the laser mark to the floor along different points of the line (using a piece of wood to 'cut off' the beam so I could measure). In the center of this laser line, it sags 3/4 of an inch (and then tapers back to level on both sides to the wall). Hope that explains it better.

I figured you were using a laser Nick. I'm with you on that, but that is not how you check a floor for flatness. Outside wall to outside wall is too much distance to really tell you anything. Plus if using a laser for checking flatness make sure the self-leveling feature is turned off.

Do what I suggested, go to the centered archway and measure back 4 or 5' in both directions. Put your laser down on one mark (lock it so it does not try to level) and point the line to the opposite mark and then measure down. A tight string or long straight edge would work alot better than a laser.

What you need to determine is how much the floor is out in a 6', 8', or 10. span. . You do understand we are talking flat, or in plane, and not level. Level has nothing to do with your figuring out flatness.

I'm a little confused by that comment-can you explain more?

I went back and leveled a string the distance of the room and measured from the floor to the string to get a good measurement. What I originally thought was wrong is not exactly right-here is what is happening-for simplistic sake just imagine one big room that is 24 feet long from outside wall to outside wall. Well, measured out from each outside wall the floor dips down a hair over 1/2 of an inch spanned over 5-7 feet measured from the walls. At this point the floor then levels out to be nearly perfect.

So from one outside wall the floor dips 1/2 of an inch in 5-7 feet-is pretty much level the next 10 feet or so in the middle and then raises back up about 1/2 of an inch over 5-7 feet to meet the other outside wall.

What are my options here?

Don't get level confused with FLAT.

The general specifications for substrate flatness is

1/8" in 6' radius

to

3/16" in 10' radius

Okay I think I got it now-So disregard the fact the floor is not level and just go around like Jerry had said with a 6-8 feet straight edge and make sure it is flat within the parameters you have set.

You won't be able to notice a 1/2 inch out of level floor (over 7 feet) with the clothed eye, right? The floor I took off you sure as heck didnt notice but that was 80 years old and very beat up and has no gloss like the new one i am putting down.