need to replace floor joist without under acsess - DIY Chatroom

bjlffire · 10-19-2009, 01:52 AM

My mother in law's house has 2 rooms (11 1/2 x 26 feet) in the back of the that does not have crawl space or any way to get under.

Floor is bouncy and very uneven.

I think the floor joist and beams need to be replaced.

Where to start?
I guess I need to remove all the flooring to see what is there.
dig out and pour some footings for the new beams.
maybe put down some plastic sheeting
start haning new joists.

Anything else?

Thanks

Just Bill · 10-19-2009, 08:14 AM

You need to get under the floor, but not thru the floor. There should some access into a crawl space, or you need to make one. The floor does not just sit on the ground.

Ron6519 · 10-19-2009, 01:57 PM

Bill is such the optomist!!
Your plan sounds feasible, but don't be surprised if you find insect/water damage to both the joists and sill plates. The room might not even have a footing or foundation from your description.
It sounds like a patio or three season porch illegally converted into living space.
After you open it up, the plan might need to be adapted to the conditions you find.
Ron

willcmjr · 10-20-2009, 09:06 PM

I agree that there isn't much advice we can give. You're going to have to get under to see what the structure is, or pull up some flooring. I have a feeling you're not going to like what you see. Sounds like this could be one big a** can of worms!

You may quickly find your self progressing from a crowbar, to a bigger crowbar, to a sledgehammer, to a bulldozer.

Thurman · 10-22-2009, 01:40 PM

What type of flooring are you dealing with? Individual boards, carpeted, layered (vinyl) flooring? Almost regardless of what you have, I would seriously consider removing something to gain access to view what is underneath the flooring. It sounds as if we all agree that you need to have access to what is underneath your flooring material to assess what problems you have, then plan on your solution. Good Luck, David

jogr · 10-22-2009, 07:13 PM

Assuming that you have and want to continue a good relationship with your MIL I'd suggest that you start with cutting a small access hatch (big enough that you can wriggle through if you find there is room under the joists) in the floor to find out exactly what your dealing with before you start ripping up floor boards. No point pulling up all the floor boards to start.

Then you can develop a plan based on reality rather than assumptions which will hopefully reduce the disruption time. Explain to Mom that you need to cut the hatch and work with her to locate the best location that will give you the info you need without disrupting the use of the room too much. You should be able to pop the hatch right back in place temporarily while you formulate a plan and get materials.

bjlffire · 10-31-2009, 11:46 PM

Pulled up the TG hardwood today, 2x8 floor joist setting on the dirt.
Some old termite damage.

I think I can cinder block the center wall and fill it with concrete.
Put down the foam and then the snap in wood simulate.

ralphfravel · 11-01-2009, 06:50 PM

In the last month I went through an exercise like you're going through and I want to tell you that while there may be a lot of work to do, it's all doable. In my case, I hired a carpenter to work with me. On the first day, we demolished the floor in the bedroom, taking us down to sand under the cabin. We found lots of dry rot due to non-PT wood. It then took the next two days to figure how to use the existing foundational wall, sister in some additional green wood beams and joists, cover the sand with 6 mill poly to reduce moisture vapor from the ground, add a first 3/4" green plywood layer, 15# roofing paper and then 3/4" OSB. The result was a solid floor that should last a long time. Good luck and have fun making the improvements.

bjlffire · 11-07-2009, 12:10 AM

Well I have all the flooring up and it is not as bad as I was excpecting.
I need to replace 2 joist.

The big problem I found is the main beam in these rooms is rotted and I need to replace.

The beam is gone in the back and getting questionable in front. It is an old rough sawn 8x8, looks like it came right from the mill.

What would be the best way to replace this?

The beam is 35 ft long supported about every 8ft till the back where it is on the ground for about 8ft.

Ron6519 · 11-07-2009, 10:02 AM

Quote:

Originally Posted by bjlffire

Well I have all the flooring up and it is not as bad as I was excpecting.
I need to replace 2 joist.

The big problem I found is the main beam in these rooms is rotted and I need to replace.

The beam is gone in the back and getting questionable in front. It is an old rough sawn 8x8, looks like it came right from the mill.

What would be the best way to replace this?

The beam is 35 ft long supported about every 8ft till the back where it is on the ground for about 8ft.

The first thing I'd do is evaluate the current supports to see if they will be up to the task for the job. Then escavate the "ground" section and place the needed supports for the new beam.
How you redo the beam will depend on the largest size joists you can get down there. I would use pressure treated wood and at a minimum, double the joists. You'll offset the beam ends and make sure they land on a support. I would use galvanized 1/2" carraige bolts every 16" to connect the beam together. At some point in the rebuild process, I would have the area termite treated and cover the ground with a 6 ml plastic.
Ron

RobQuillin · 11-07-2009, 11:28 PM

How old is the house. It almost sounds like it is and old balloon consructed home. If this is the case then check to see if the beam is mortised into another one. Also if the house is this old then you have to check to see what the foundation is doing. Back then they quite often didnt dig their foundations very deep. The foundation could only be a foot or two deep. If this is the case then if you start digging out to make room for the joists you could undermind your footing and start making the foundation to give way. I say footing when in reality they quite often didn't have a footing but just some bricks layed flat. Make sure you check all these before you get too gun hoe or you might get into more than you are ready for.

bjlffire · 11-09-2009, 12:57 AM

If I build a 2x4 framed wall on bothsides of the old beam can I remove and replace with say 4 2x10's?
Reinstall supports and be good to go.