Can I eliminate the joists?

Question

Home built in 1850 with 2nd floor having 6'-6" ceiling height, I want to install 2x4 collar ties at every rafter at a height of 8'-6" then cut the joists. Can this be done? Any suggestions and/or tips will be greatly appreciated. Yes, I will probly be here a long time so selling is not an option. Thanks for any help

Answer 1

The most important thing to ask is, Is this a structural supporting wall ?

That means does this wall support anything else, like the roof or another set of beams overhead ?


I strongly suggest you contact a "structural engineer" to figure out whether you even should be messing with this wall.

they should not be too expensive, $75.00 to $250.00 to let you know, and that is a lot cheaper than having to rebuild your house.

Now even if it is a wall that supports something else, it is not the end of the world. Ask them how you can get around its problem, that is why they are there.

believe me it is so worth paying a little now to save you a lot of headaches latter.

good luck and post a before and after picture for us.
OK ?

Answer 2

Yes , it is commonly done to create a" cathedral "ceiling.
I used collar ties as mentioned to gain height & cut in a skylight. on a short peaked extension w/ a 12/6 pitch.
Had advice from a carpenter buddy & would not have been as confident on a larger project.
One concern would be pushing out tops of sidewalls if the rafters sag at all when the ceiling joists are cut out.
Thats where having a friend who" knows" comes in.
The 6'-6" height of walls is a plus since it would be stiffer than an 8' wall.
Also a plus if ceiling joists do not appear to be tieing the roof rafters to top plate & are just there to support the ceiling.
Definitely do-able , but getting solid advice from someone who can actually see the place would be way to go.
Best regards

Answer 3

You should get it looked at by a structural engineer. It will depend on the connection detail of the rafters to the wall plate and size of rafters. The existing joists are acting as collar ties (holding the walls from spreading). As the higher replacement joists/ties are moved up on the rafters, the bending moment in the rafters will increase which would generally require the rafters to be larger than they would currently need to be. The rafters may have the extra capacity (to the current code) or they may not. So it depends if the rafters were oversized to start with. Also the connection of the rafters to the walls may be a concern. A standard birdmouth notch and adequate fasteners would be necessary. Currently the existing joists are very likely also connected to the walls sharing the tensile load. After the existing joists are moved up, the rafter to wall connection will have to carry full load. So the best answer is that is depends on the rafter size and rafter/wall connection detail. I would have more concern about both things given the age of the building.

Answer 4

I believe you would be OK installing collar ties to raise the ceiling height. If you install the collar ties before removing the ceiling joists, there should be no problem at all. I'd get a building permit first and do things y the book, just in case there is ever an insurance claim in the future. I made a cathedral ceiling once by installing collar ties and removing the existing joists. Looked fantastic. Alot of work, but well worth it, especially in your case as a 6'6" ceiling is looooooow. Good luck and take your time.

Answer 5

Yes you can, you will need to install the new collar ties before you remove the old. use carriage bolts to bolt them together.
2or 3 3/8 with washer and nuts long enough to go through the rafter and the collar. Definitely get permission and watch out for historical preservation requirements. You may be able to reuse the old collars and save on some lumber expense.
Good luck.

Answer 6

The web of the I-beam is 3/8" or 1/2" thick material, not very substantial, compared to a 1-1/2" thick solid beam. As such, the web does not dampen the sound, instead it reflects sound like a drum. You need to isolate the fan box from the I-beam to minimize fan vibrations from being transferred to the I-beam web. Sandwich two rubber faucet washers at each point where the fan box is screwed to the I-beam: one washer between the box and web, and another between the box and under the screw head. Maybe add a flat washer between the screw head and adjacent washer. If you have more room to work in the ceiling, a better way is to screw the fan box to a strip of wood (e.g. a furring strip) with rubber isolation washers, then screw the strip of wood to the I-beam, again with more isolation washers, but using a separate set of screws. That way, there will not be a direct transmission path for sound to travel directly to the I-beam web. Good luck.