Need suggestions repairing a floor joist


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Sep 12, 2012 - 01:12pm PT
(no studs or lath in these walls; it's plaster direct on the stone).

No studs. What in god's name is the second floor sitting on?

They just embedded another offset in the exterior stone veneer to hold the floor?

Those guys were really excellent masons. And they knew it. No motion at all in 153 years.

Stone masons in the UK back in 1600 designed their rubble stone walls so they could move and yet still function. 1000 year old buildings that move and yet still work.

Your house can't move?

Oh. My props. Truly great thread.

Trad climber
Sep 12, 2012 - 01:29pm PT
Contact 'This Old House' at PBS to do the job for you.

Relocate the radiator and plumbing elsewhere, out of the way.

philadelphia, pa
Topic Author's Reply - Sep 12, 2012 - 02:32pm PT
No studs. What in god's name is the second floor sitting on?

Unless I'm mis-remembering, the 2nd floor joists are done the same as the 1st floor joists and sitting in mortared alcoves like this:

I'll try and find the pics from the bathroom demo, as it should show what was done. I will say I think I had to toe nail blocking between the joists along the wall to have something to attach the plywood subfloor to, as the only thing there was the joists on 16" centers and exposed stone.

Oh, and the beams in the bathroom were level within 1/8" over 4 feet both directions. So yeah, the place is *solid*.

Ice climber
chingadero de chula vista
Sep 12, 2012 - 02:42pm PT
VCT tiles, drywall mud and sheathing, plaster and lath, pipe insulation at the elbows and siding shingles from basically the dawn of time until the mid 80's should be suspect. This is a big deal in commercial reno's but seems to be not taken seriously in single dwelling wood frame residential renovations.

This is rather disconcerting to read. Are you pretty sure about this?


Technically expert, safe belayer, can lead if easy
Sep 12, 2012 - 02:45pm PT
The floor joists in my house (ca 1942) sit in alcoves like that, with overly-spanned support posts. The floor felt like a trampoline. First thing I did was double up the post supports, which made a big difference.

Of greater concern were the ends of the beams in the alcoves- they were exposed to they outside, and end grain had been fairly penetrated & rotted by water. That last pic looks pretty damn good for it's age, though the wood looks discolored (image quality, perhaps).

philadelphia, pa
Topic Author's Reply - Sep 12, 2012 - 02:59pm PT
@zBrown- Yup, what you quoted is correct. Asbestos is on all sorts of old construction materials, and most DIY'rs are ignorant of it. There were asbestos tiles in the bathroom and I suspect the ones in the mud room are as well, but other than that this house was/is surprisingly asbestos-free. I attribute it to the thermal mass of the house... Even with no insulation it takes 3 weeks of 90+ degree weather to bring the interior above 74. Likewise in the winter; the house stays surprisingly warm now that we replaced the windows.

philadelphia, pa
Topic Author's Reply - Sep 12, 2012 - 03:03pm PT
This, I can live with:

Not perfect, but good enough for what it needs to do. Tomorrow I'll scab in a pair of treated 2x8, add a post to support the joint and then refigure the piping. Calling it quits early today, as we're having people over for dinner and I have to start cooking.

Btw, thanks again for all the help, Folks. If you ever run into me during your travels, I owe you a tasty beverage.


Oh- if you can make out the grey-ish smooth stone to the left of the end of the joist, that's the the stone threshold just outside the front door. It's a solid block of marble measuring ~18" x 48" x 6" thick and is worn almost 1/4" deep in the two spots where people usually step.

philadelphia, pa
Topic Author's Reply - Sep 12, 2012 - 04:40pm PT
Found the pic of the bathroom demo, and yup, the joists are set into alcoves in the stone wall. And are massive, at 3" x 12".

I could't find a pic showing whether the joists are supported in the middle of the house, and frankly I can't remember if they are or not. I did notice today that the strip flooring actually passes *under* the interior walls, which points to the walls going in after the finished floor. Weird.

Funny story- while putting in the bathroom floor my buddy, who weighs in at 180+, stood up from where he was sitting to measure something. I look over, and there he was standing on the plaster and lathe of the ceiling below. Needless to say, I suggested he sit down real gentle like. Amazed the ceiling held him, and good thing it did, as he was straddling one of the joists.

Oh, question on the epoxy for sealing the dry rot in the subfloor... any suggestions what to use? I stopped by the large independent construction place and described what I wanted to do, but they said they didn't have anything appropriate and should try HD. Best thing I could find at HD was Bondo, which likely isn't what I want. Any suggestions?

The Warbler

the edge of America
Sep 12, 2012 - 05:05pm PT
If you want it to penetrate the dry rot try : CPES Clear Penetrating Epoxy Sealer.

This will strengthen it and prep it for paint.

philadelphia, pa
Topic Author's Reply - Sep 12, 2012 - 10:56pm PT
Thanks, Warbler! Looking at their wares it would seem the "proper" repair would be that thin, brushed on epoxy followed by the thick, playdough-esque one (to build up the missing material prior to scabbing in a new joist). Pretty amazing stuff.

That said, I thing I'm going to punt on it and simply scab in a "temporary" repair joist. Long story short, as mentioned earlier in the thread the big issue is actually the water in the basement and right before I headed home I realized I had a moisture meter sitting in the corner the radiator I pulled this morning came out of (chasing down a leak in the stucco). Turns out *ALL* of the wood in the basement reads 16-18%, which is far from ideal.

Clearly fixing the water issue should be top of the list, and thankfully I've been prepping SWMBO for this contingency (abandoning fixing the plaster and digging a French Drain instead). I fully expect all of the water in the hole left from that fake pitcher pump to be there in the morning, which should drive home the point that fixing the water issue takes precedence over making it look nice (been some disagreement on the order of things up to this point). I pitched the idea of digging the drain this evening and it went as poorly as expected, but it's really looking like we need to accept that it won't be rented by October and we've got another 6 months/year until it's ready for that sort of thing. Time will tell, and I'm still enjoying daydreaming about the 30' x 40' two-story barn/workshop I'd potentially end up with if we ever finish this project (the garage is 30' x 40', had a flat roof which collapsed, and is on hold until we finish the main house and get it rented. Plan is for that to be my workshop to run a climbing gear company out of, but at the moment I'm thinking that's a pipe dream even though I've had prototypes out in the field for the past year or so... :-(


philadelphia, pa
Topic Author's Reply - Sep 13, 2012 - 01:52pm PT
Well Folks, in retrospect that really wasn't do bad. Ended up using a single treated 2x8, as even that's probably overkill for the load on that one small section of floor and it allows me to avoid notching for the pipes (will add a couple 45's to move them out anyway). Rather than bothering with a post in the corner, I simply cut it long, shoved it into the alcove and knocked a suitably sized flat rock under it when jacked a bit past where it needed to be.

On the other end I put a temporary 4x4 treated post on a large chunk of cinder block, which will get replaced with a screw jack when I get a chance to fab up a steel plate to tie the two joists together.

Thanks again for all the help! I'm off to throw a couple nails in it and then rework the pipes...


Mountain climber
The Other Monrovia- CA
Sep 13, 2012 - 02:05pm PT
Good job!
I hope you sprayed something to kill the dry rot in the subfloor before you
put the joist in. You still could to some extent. I assume you are going
to connect the joists and the joists to the post with some framing anchors.
I know you don't have too much shaking back there but since you're down there...

philadelphia, pa
Topic Author's Reply - Sep 13, 2012 - 03:21pm PT
Holding off treating the dry rot for now, as the whole basement needs it once I get the water situation sorted out. And yup, the plate I'll be making will be maybe 2' long and L-shaped in cross section, to not only tie the joists together but also support them from underneath. I'll also weld the screwjack to it to help prevent it from tipping out should something move.

Social climber
Sep 13, 2012 - 03:56pm PT
This repair looks great. I think you're on the right track. Repairs as needed, and keep 'em simple.

MeanwhileFrom the pictures you've posted I agree that dampness is the major, long term problem.
Pretty standard measures should get you most of the way there. French Drain. Gutters and downspouts (if you don't already have them?), lanscape the ground outside to slope away from the house for 6 feet or so. If one side is too high for this, try to construct a rough, basic swale to channel surface moisture around the perimeter to where it can drain away.

Not sure about the pitcher pump you mention. Kinda sounds like a hand operated version of a sump pump. So, you maybe have a high water table? flooding or drainnage into the basement?

If so, you may need a modern sump pump. Put it in the lowest bit of the basement. These work great. Here's one idea of how to install it:,,1631605,00.html

For long term reliability install two. They do get clogged and stop pumping occasionally.

Removing all the dampness from the floors, lumber, stone, mortar can take months, even years, with such burly construction.

You can rent or buy a de-humifier to kickstart the process. Never used one myself:

They are used more typically for sudden flooding issues, to dry out building materials before they get damaged by damp. May be a waste of time for your situation where the dampness has been around for years.

Simpler might be to add a source of heat for the basement, at least for a few months. As air gets warmer it dries out. Good luck.

Ice climber
chingadero de chula vista
Sep 13, 2012 - 05:25pm PT
On July 12, 1989, EPA issued a final rule banning most asbestos-containing products.

I'd say asbestos is a real can of worms. I'd gotten it in my head somehow that it was the 1950's. I still like "Ike", but he shoulda done more here.

For anyone interested:


Sport climber
Boulder, Colorado!
Sep 13, 2012 - 05:40pm PT
Another awesome thread! Love all the insight and photos.
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