Need suggestions repairing a floor joist


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Trad climber
Placerville, California
Sep 10, 2012 - 03:56pm PT
the process is so simple,
you skirt the ill joist with a skin (plywood works great),
running the skirt a couple of feet beyond the boundary of the rot;
then drill a small hole thru the skirt, 3/8" into the parent member,
and inject (the epoxy is sold with application tools) the epoxy thru
the hole.

allow this to cure for a couple of days,
strip off the skirt and go climbing.

i'd estimate the cost to repair this +/- 36" of meat
at about 300 bucks.

i can provide a supplier contact if you are curious.
he's out here in california though.

we use his epoxy to repair micro-failures in structural concrete
members all of the time.

The Warbler

the edge of America
Sep 10, 2012 - 04:00pm PT
That sounds like a different product and method than I'm familiar with, Norwegian. The product I've used is to prep rotten wood for paint .

It makes sense, depending on the cost and hassle involved as compared to a more caveman repair.

Social climber
Sep 10, 2012 - 04:07pm PT
Best of luck with the project, adatesman! I'm living in a 15 year old home on an island in Puget Sound, and while we love the west coast, we both grew up in old towns and old homes on the east coast. As beautiful as our property is, this house is never going to have the character of something built in the 1800's. I completely understand why you're there.

Social climber
Sep 10, 2012 - 04:18pm PT
Hey Norwegian, I am curious! Can you post the name of the brand or the supplier? It seems like it would need to be injected under some pressure, although the cure time (a couple of days) may allow diffusion into the wood at low pressure. Longer cure times = greater strength for epoxies, so this makes some sense.

(Like my penis.)

philadelphia, pa
Topic Author's Reply - Sep 10, 2012 - 04:48pm PT
Ha! Some (unrelated) good news! When I went out back to get the ladder to reprint the exterior wall I noticed that the weird aluminum telescoping pole thing I almost took to the scrapper a couple weeks back was actually a really nice 10' painter's pole! The painting job I expected to take several sucky hours up and down the ladder ended up only taking 30 minutes from the ground! Woo-hoo!!!

Unfortunately this means I'm back on the floor joist project now...

Let's see what other details i've left out...

1. It's not that I *can't* move the pipes, it's just that getting this system drained is a major PITA and given it's age I'm not so sure the fittings in the radiator will come out cleanly to allow repositioning the pipes. Plus I suspect the damage is really old and predates the current pipes (everything's dry and the system's been full almost a year with no additional water needed), so would prefer not opening another can of worms. I suppose I could turn on the heat and check for leaks... Probably a good idea. Will do that first thing tomorrow. But in the meantime, moving them would mean moving the riser to the upstairs, which wouldn't be quick or easy.

2. Assuming I cut out the joist and scab in a new one (with supports on either end), how does the floor get attached to it? I assume toe nail (probably the wrong term) from underneath? There isn't really a subfloor per se; there's the original wide plank direct on the joists, followed by 1890's-1910's strip on top of that. Most of the original wide plank in that corner is still solid, so nailing upwards on an angle should find something to bite into.

3. No chance whatsoever at getting to the other side of the foundation. The walls are ~21" thick mortared stone, and the foundation is something more than that and goes down at least 6 feet. Plus that wall has a cement porch in front of it, and that slab is easily 6" thick. On a side note, I once did a ballpark calculation for the weight of the house and came up with something like 3-400 tons. Just for the exterior walls.

4. Wege's epoxy is out, as my method of testing soundness was hitting the joist with a hammer and large chunks fell away. Side note- chunks were bone dry and turned to dust, hence thinking there's no longer a leak. The temporary support is actually sitting on pieces of concrete... The brown stuff if what fell off the joist when the hammer went through it. No evidence of termites either, btw. A couple very unhappy plants that rooted through the foundation and tried to sprout, though.



Mountain climber
The Other Monrovia- CA
Sep 10, 2012 - 05:08pm PT
This is what I would do.
1. Figure out how to move the pipe just an inch or two away from the wall.
Can't be that tough.
2. Cut the old guy a safe distance past the rotten section at a 3 to 1 angle.
I would make the initial cut with a circular saw and then finish up with a
sawzall and/or hand saw.
3. Chisel the old piece bearing in mind the floor board nails are gonna
cause you grief.
4. Cut your new section and glue and wedge it in place with maybe a lag up
through the scarf joint.
5. Reinforce the scarf joint with a treated 2x with lots of glue and
rot-proof screws or nails.
6. Put a post under the scarf joint with a framing connector to the beam.

Easy peasy! ;-)

I guess you can forget the post. It looked like there was room for a post
but I guess there isn't.
The Warbler

the edge of America
Sep 10, 2012 - 05:13pm PT
Prep the old joist, decide on your plumbing solution. Put two bottle jacks under the 4x8 which will be on edge against the old one, jack each one up evenly until it's obvious by sight and sound you're up tight and even against the underside of the floor boards. Hang your stubby posts with brackets off the underside of the 4x8 with nice square cuts on the post tops and tight joints, then pour your footings either around the wood directly, or around metal post bases attached to the bottom of each post and extending into the concrete.

Let it dry and pull the jacks.

Trad climber
Placerville, California
Sep 10, 2012 - 05:17pm PT
dude just lay neath your abode
and chew upon her skeleton;
swallow her splinters,
digest something beyond you,
excrete new understanding
and this mock enlightenment
you can stuff 'neath your self-sentenced cell
and that pile o' misunderstanding
will prolly prop you up
for another epoch or two.

here if you want,
you can borrow, i mean have, my shoe.

because tucker already strides mine other.

and he lives inna cave 'o stone that
jesus walked on by enroute to his tomb,
dumb f*#k!

we should be praying to tucker not to jesus.
no more wars.

philadelphia, pa
Topic Author's Reply - Sep 10, 2012 - 05:22pm PT
Lost me on the 3:1 angle thing, Reilly.... Increasing area of the glue joint? And to be honest, there's a goodly chance I'll be removing the pipes for access, since chances are I'll clip them with a sawzall anyway, so way as well at least reduce the notch to a small one at top rather than the whole height of the joist. Plus then I can cut the joist at the middle of the house (where it happens to be supported and then sneak the new one into the alcove and shim as necessary. Liking that plan even though it means cutting into the pipes.

Btw, this is just the warmup act for the main event in the dining room....

Been working up the nerve to tackle this one for months, as it requires excavating that half of the basement (some joists are sitting on dirt, at leat 4 need outright replacement). Fortunately farming has fallen out of fashion around here (Philadelphia, PA), which means I can likely pick up an old hay/grain conveyor for a couple hundred bucks and put one end in the basement to avoid needing a bucket brigade.

Long story short: beautiful historic houses need upkeep, and the people we bough this from did nothing in the 60 years they owned it.
Roger Breedlove

Cleveland Heights, Ohio
Sep 10, 2012 - 05:42pm PT
Cut the rotten joist out and replace it. If it is set into stone, make two pieces and bolt them together with a steel plate that ends before you get to your pipe. I know that this sounds like lots of work, but all the complexity of trying to make a smaller repair, shore-up and work around what's there, and make room for the plumbing is more work and has much more uncertainty, in my opinion.

Just to tell the story, when I worked in Squaw Valley, a new lift was installed to the upper slopes (probably in 1971 or so). One of the towers on the top of a rock ridge was about 2 feet too short. I think it was about 50' high and set at a slight angle. I drove a crew of Swiss guys up there with a welder and generator. They secured the top of the tower with come-alongs anchored to trees and rocks set back about 150 feet or so. They scabbed steel buttresses about 6 feet high onto the tower's base plate with matching flanges welded to the tower above a cut line about 2 feet off the concrete. The welder cut the 24" diameter tower, and the engineering crew, using wenches attached to the top of the buttresses, jacked it up 2 feet. The welder fitted in a new section, and welded it together. Presto, the tower was two feet taller and the lift opened on time.

The hardest part in replacing your joist will probably be figuring out how to get direct force on the new joist to get it into place. It doesn't look like you can get directly under it. Using levers would work.

Sportbikeville & Yucca brevifolia
Sep 10, 2012 - 05:45pm PT
Werner's idea will cost less and work best.

Near Boston
Sep 10, 2012 - 07:03pm PT
I feel your pain. I have replaced a joist just like yours but I could access it from both sides.
I jacked up the floor on a temporary joist and excavated out the old one. I then liberally placed epoxy and sledge hammered in a new pressure treated section.
To attach the flooring I pulled off the molding on the wall and nailed the flooring down there; with the molding on you never see the nails.

Trad climber
Sep 10, 2012 - 07:04pm PT
I have a old commercial building/warehouse that is of massive timbers, and had the same problem with the joist. As suggested, either pour some concrete pads or place some premade ones for a base for the house jacks. Support your structure/floor load with the jacks, and cut the old joist away with a chainsaw. Then replace it and use old bridge or railroad ties for support, again cut with a chainsaw. Treated, burly and cheap. Nothing wrong with a little overkill.

Sep 10, 2012 - 07:51pm PT
All this talk blah blah blah

Now if all of us workers would be there right now with all our know how and tools we'd have that bitch shored up by now.

Either that or we'd all be still standing in front of the house arguing about how to do it as the sun sinks in the west.


Ice climber
Pomfert VT
Sep 10, 2012 - 08:25pm PT
I spent the last two years doing this stuff for a job. like everone else says. Dig some holes, poar pads, jack er up, sawzal the old crap out and get a new pressure treated joist in there w/ steep plate. Is LVL as resistant to rot? that stuff is real floppy so you would want to bolt a few of em together. I would just go with pressure treated.

Mountain climber
honeoye falls,ny,sawdust does not work like chalk
Sep 10, 2012 - 09:51pm PT
hello,im a 35 year carpenter,i would remove the exterior siding,freeze board,then replace the existing sill beam ,find someone to mill you the exact size beam,and replace at least a 8 foot section.knotch were you would like your pipe and mortar under the lasted like that this long, the repair will only out live the surrounding area by about our kids,kids.reside.

Sep 10, 2012 - 09:54pm PT
When we bought our 1854 house we needed new first floor joists--along with many other needed repairs. Instead of showing off a new, fancy kitchen, I"d show off my new expensive floor joists! Ha ha!

Social climber
So Cal
Sep 10, 2012 - 10:28pm PT
So far everyone has ignored or brushed off the crux issue.

You have a leaking condensate return.

Gotta fix that first and identify if the issue is 60+ YO pipe that is getting ready to bust loose elsewhere.

If the pipe didn't leak, you wouldn't have to move it, or replace the joist.

Re-insulating the steam lines while you are at it, including the condensate returns would probably pay for itself in a year from reduced heating oil costs.

Beware of asbestos though on the old steam lines. Getting rid of that would be a fortune.

Fix the problem first then tackle the symptom.

Mountain climber
honeoye falls,ny,sawdust does not work like chalk
Sep 10, 2012 - 10:38pm PT
if the pipe is leaking or it is condensation,heat pipes sweat,fixing that first would be a given.carpentry issues ,same as above.the question was ,repairing an old floor joist

Social climber
So Cal
Sep 10, 2012 - 10:58pm PT
Heating lines don't "sweat", unless they are leaking steam or condensate.

Chilled water lines sweat all the time.
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