leveling floor / replacing floor joists

[trance]

Ok, here's my latest:

1 room (at second floor) has a sagging floor. Floor sags about 1.5" from edges to center. Sag is at side of room w/door, towards middle of floor and window, the floor is flat.

I'm guessing the sag is due to a poor install of a heater duct, cutting joist down to nothing. That joist has probably mostly failed, causing extra load to be transfered to adjoining joists.

Of course, the joist that has failed is right under the wall. Wall is not structural, but of course, has it's own dead load.

Question: can I remove the joist under the wall w/o wall coming down on my head?

Question: Can I replace sagged joists/failed joists w/o removing floor above? (Floor above is 1.25" thick popular T&G).

Question: of course, the wall above has also "sagged" over the years, so a new joist under it won't "fit". Can I cut off the bottom of the wall to fit the joist? (Removing and replacing the wall is NOT an option.)

Thought: sister joists to each side of failed joist. Cut off bottom of failed joist. Thoughts???

Thought: easier to sister joists and live with the sag? (prevent further damage). Thoughts??

Question: 135 year old house's joists are not deep enough to meet current code for span. How to deal with that when replacing joists? Double up joists? Space joists more frequently? (Like every 12" instead of 16"?)

Allright. Enough!! :eek:

[Doug Aleshire]

trance,

Well this is a good one for sure. First off, home is 135 years old means that it is a "stick built" roof system, right? This means that you have loads falling on interior walls as well. Have you already opened this area up to see exactly what is there?

Question: can I remove the joist under the wall w/o wall coming down on my head?

Answer - Well this is a good question but what is exactly there now? - is this viewable and if not, it needs to be.

Question: Can I replace sagged joists/failed joists w/o removing floor above? (Floor above is 1.25" thick popular T&G).

Answer - How do you remove an existing joist and salvage the floor above that has been nailed in? This endeavor may be difficult to do but temp bracing must be done and if possible a metal saw blade in a recip saw might cut the nails for you - I stress "might".

Question: of course, the wall above has also "sagged" over the years, so a new joist under it won't "fit". Can I cut off the bottom of the wall to fit the joist? (Removing and replacing the wall is NOT an option.)

Answer - If you say it is not an option then my question would be why not?

Thought: sister joists to each side of failed joist. Cut off bottom of failed joist. Thoughts???

Answer - I would cut NOTHING - sistering could be done but what exactly are we talking about - what size wood would fit? How much has been cut out to cause this sag?

Thought: easier to sister joists and live with the sag? (prevent further damage). Thoughts??

Answer - Again, what is the size and span of damaged area?

Question: 135 year old house's joists are not deep enough to meet current code for span. How to deal with that when replacing joists? Double up joists? Space joists more frequently? (Like every 12" instead of 16"?)

Answer - Again repeat with need to know more before even suggesting anything.

Just need more answers and even then you need to get someone to look at this before trying anything. This isn't a project that I would want to chance on mistakes being made.

Hope this helps somewhat