Basically they are saying if a floor is sloping over a 1 2 to 1 inch in twenty feet then there is concern.
Floor sagging 2 inches.
You can also use a 4 foot carpenter s level placed on top of a 2 by 4 inch board to check level as well.
This house has an 18 inch tall crawl with no access.
A simple way to check floor sag is to set a small rolling object on the floor and watch.
Floors that slope 2 or 3 inches in 20 feet would be a very serious concern.
Depending upon the conditions it is possible to strengthen or repair existing framing members such as floor joists or roof rafters by adding reinforcing material sandwiching the member on either side with plywood is sometimes worthwhile but the plywood must be installed correctly for greatest strength.
The extra two inches of vertical distance when a floor is framed with 2 x 10 joists rather than 2 x 12s can be quite important for example.
Common sense tells you that large floor joists can carry more load and spacing joists closer together also increases the load bearing capacity of a floor.
Floor slopes and slants are common in old houses.
No one likes the feel of a supposedly solid floor bouncing or sagging underfoot.
A friend of mine is thinking of buying a house it needs alot of work mostly cosmetic however i walked threw it with him today and i noticed the floors were saging about 1 to 2 inches towards the center of the house.
How to fix springy and spongy floors.
Nearly all will say that if a floor slopes 1 and 1 2 inches in twenty feet or more that there should be further investigation.
Insert 2 inch decking screws 8 inches apart in the subfloor over each.
Except for that slope the floor itself might be flat.
But larger is not always better when builders are constructing a home or adding a room addition.
I ve remedied this problem before but in a house with a basement.
We got muddy because we were in a dirt crawlspace doing just that crawling.
A slant slope situation might be one where over the course of 15 or 20 horizontal feet the floor slopes down one or two inches.
Floors are rarely perfectly level.
If the area is very large use a long straight 2 in 4 in 5 1 cm 10 2 cm board and set your level on top of it.
Total cost was less than 200 while a pro would charge 500 1000.
This job took two people one afternoon.
Cost time and skills.
Floors that slant or slope.