Adding more floor joists in a crawlspace. Originals are 5' OC and need more support


I just bought a 1956 ranch house in Portland, OR and am facing an issue. I've gutted the bathroom for a remodel and it's down to the studs. There was a bit of water damage to the subfloor around the shower/tub so I decided to replace the whole thing.

In the process, I discovered the floor joists are approximately 5' on center 4x8 which is certainly not up to modern day code. On top of that is tongue in groove 2x6 decking for the subfloor. The floor is surprisingly sturdy but many people have already suggested that it would be smart to add more joists, especially since I'll be tiling the floor.

The old joists abut against the concrete foundation, kind of like a mortise and tennon joint (not sure what it's actually called). The foundation is in good condition and doesn't have any cracks and looks dry. The joists span what looks to be the entire length of the house with 4x4 pier supports every 6' or so.

My question is what's the best way to add new joists to the...

0 0

Just wanted to update this thread since it's been a couple weeks since my last post. I got the 24"x24"x8" concrete pad poured and let it cure a week. Six sacks of redi-mix was perfect, had at most a quarter sack excess. Last Saturday I laid 8 blocks, 2 side by side, 4 tiers tall, alternating the center gap n-s then e-w. I think masons call that a basketweave pattern. Anyway it turned out fine, nicely plumb and level. My mortar joints were closer to 1/4" than the 3/8" they were supposed to have been so it came out a tad shorter than was expecting but nonetheless a good first effort by the rookie.

Took the house jack into the crawl space today and made a temporary pad using 3/4" plywood, some scrap 2"x8" pieces and a couple spare blocks. Got it level and set up the jack. Was a bit apprehensive when the jack actually took the load and the beam started moving up. My sense is the jack moves up about 1/8" per revolution. The first 3/8" went easily, the next 1/4" was firm and...

0 0
0 0

In a typical home, the surface flooring (such as wood, carpet or vinyl) rests on a subfloor, which rests on joists[1] -- a series of closely spaced parallel beams that support the floor or ceiling loads. Joists are usually supported by a sill (a long horizontal timber that's the lowest part of the framework and rests on the foundation) or a girder (a large beam that's the main support of the building). When replacing rotted floor joists it's important to be sure the girder and sill are still intact. Typical costs:If only a few joists are rotted primarily at the bottom, they can be repaired using a process known as "sistering" -- after the rot is cleaned away and the timber treated to prevent more problems, a new joist is laid beside the old one and fastened to it. Total costs will depend on the extent of the damage and the ease of access to the joists (through a basement or crawlspace), but in general sistering averages $100-$300 or more per joist, and could run $1,000-$3,000...
0 0

Crawl Space Repair

If your crawl space is starting to collapse, and your floors are sagging or leaning, the crawl space joist support is the answer. It's an adjustable steel pier placed in a crawl space, between the ground and floor beams or joists for support. The bottom end of the pier is connected to a precast concrete footing and the top end is connected to the floor beams or joists.

This support system can help correct crawl space issues caused by inadequate structural design, weak foundation soils, or rotting beams and floor joists. With an adjustable, high-strength steel design, crawl space joist supports offer the fastest, most affordable way to stabilize a collapsing crawl space or lift sagging floors back to their original, level position. They are also a very effective solution for seismic...

0 0

This depends on any wires that may run under or through the floor joist. I assume what you mean by top and bottom plates are the Sill plate that rests on top of the block foundation and then the bottom wall plate that your wall studs sit on. + how many lineal feet of plates are in need of replacement- sounds like maybe 12' or so.
If the house has vinyl siding on it - it is easier, much easier than if it has brick or stone.
We have done this several times. We remove the siding up about 3' from the bottom. We then shore up the bad floor joist. We then screw a 2" x 12" up about 12" above the bottom wall plate (screwing the 2" x 12" into the studs. This makes a surface type header to hold the studs in place while we do work below.
We then cut out the bad Sill plate and replace it.
Then we remove the boxing or band board.
We then have our new floor joist handy and cut a taper of 1/4" to nothing on the end of joist(all on end going first into...

0 0

There are standard recommendations for high-performance R-values in homes, from the ground up -- R-40 for walls, for example, but typically much less for slabs (not going to enter that controversy by naming a number).

For various reasons, I'm considering building over an uninsulated crawlspace. What would you recommend as a rule-of-thumb R-value for a high-performance home, for the floor system, in this case? Since it won't be thermally buffered the way a slab would be, I'm thinking it should be closer to R-40 than, say R-10. But doing something less than R-40 would be preferable due to the complications of a floor system with that much insulation....

0 0
0 0

irst-floorjoists are placed on edge across the sills

ported by metal hangers. Check the plans for spe

to provide support and a nailing surface for the

cific information on beam and joist size, length,

Fsubfloor and a platform for walls. On a small

spacing and the direction the joists will run.

building, single joists may be able to span the entire

One problem with beams that are installed flush

foundation. On larger buildings, the joists will span

with the joists is that much of today's framing lum

from the exterior wall to a girder, beam or bearing

ber has a fairly high moisture content, and joists,

wall, where they will either butt or lap over the top.

being smaller than beams, will dry out and shrink

At the sills, they are supported and held upright by

faster. When plywood sheathing is nailed to a new

rim joists. Joist size can vary from 2x6s over girders


0 0

I that so much to ask?

All plywood is not NOT the same. That's the first thing to recognize.

A bit harder is to recognize that in every field there are professinals, who know from experience just what they need. In a fancy form, this shows as the various codes and standards that pros follow.

There are specific standards for subfloor material.While other materials might 'work,' might even be 'better,' your best way to be sure you're using the right stuff is to buy the product specifically made for the use.

Probably the biggest requirement is that it all flex together.This means tongue & groove connections between plates - or solid support under the joints. It also means that the 'grain' of the pieces all goes in the same direction. Fail to do this, and you just might cause the finish floor to fail.

Rated sub-floor material is NOT expensive,or hard to find. It's worth finding a real lumberyard; my local box store 'pro' had never heard of...

0 0
0 0

If your furnace is going full blast and you still have cold feet, the culprit may be your crawlspace insulation.

Take a look under your house. Damp, dangling insulation is a sure sign of outdated or shoddy installation. If your house was built before energy-conserving building codes were standardized in 1990, you may find no insulation at all. The U.S. Dept. of Energy currently recommends insulation with an R-value of at least R-9 in floors.

To keep things cozy underfoot, you’ll need to select the right insulation approach for your local climate. Winter temperature is the continental divide:

In moderate or dry climates without the threat of sustained subfreezing temperatures, insulation between floor joists makes sense.

Where winter temperatures are extreme, opt for insulating the walls and sealing off the crawl space entirely.

Floor Insulation for Moderate Climes

If your winter temps seldom linger below freezing, you’re in luck....

0 0

Many homeowners searching the internet for crawlspace repair information end up in home repair forums. While there is some good information out there, there are many examples of bad and outdated advice related to repairing crawlspaces. I have witnessed firsthand the results of unprofessional crawlspace repair and would like to set the record straight on what I consider to be the worst 5 crawlspace repairs I've seen.

1. Adding more foundation vents to the crawlspace - Old buiding codes and bad advice have resulted in homeowners adding more vents to their crawlspace in order to dry the high moisture content in their crawlspaces. The thinking behind ventilation was that air circulation would force the moisture in the crawl space air to end up outside. Through testing, it has been proven that warm, humid outdoor air brought into the crawl space through foundation vents in the summer can lead to increased moisture levels in the crawlspace. Also, the air movement in a home does...

0 0
0 0
0 0
0 0

Clean, Cool and Energy Efficient!

Our Closed Crawl Spaces are the most energy efficient, durable, and low maintenance crawl spaces on the market! We use radiant barrier liners, non-toxic mold coatings and a patent pending fresh air ventilation systems which eliminates the need for a dehumidifier.

Most homes get their “fresh air” from the crawl space. Unfortunately, open vented crawl spaces tend to have serious mold, radon, bacteria, and insect issues. Because of the related health risks, these contaminants should not be allowed to enter your home! Our radiant barrier closed crawl spaces are air, water & bug tight. They are clean, dry and mold free. When we finish with your crawl space it will have better air quality than your home AND be significantly more energy efficient which makes your home healthier and more...

0 0

SmartJack® Benefits

SmartJack® is a high-capacity, fully-adjustable steel pier. Designed to stop settling and can raise your sagging floor back to the proper level. Steel piers can be easily adjusted if future settling occurs.

Looking for product pricing?

SmartJack® is only available from a certified installer in your area. Contact us to request an inspection & get a free cost estimate to have it installed in your home.

A smart fix. SmartJack® support posts will straighten and strengthen sagging, bouncy floors above a crawl space.

Support posts for a permanent fix for sagging, bouncy floors

Are you bothered by sagging, bouncy floors above a crawl space? This is a common problem. Sagging, bouncy floors indicate a serious structural problem that will worsen over time. These conditions can make floors unsafe, while also causing unsightly cracks in wallboard and beneath baseboard molding.

What causes sagging, bouncy...

0 0