Need “solid” suggestions for gaining “support”
Installing an 85 gallon water heater in the laundry room. Need to beef up two 12′ 2×8’s (16″ oc) that span this section of this flloor. Sistering the joists is not a desirable option due to framing, wiring, and plumbing obstacles. Thinking that a sleeper beneath the joists might be a more practical solution.
What’s the best method for constructing a sleeper?
TIA
Replies
MW, your span isn't that long-normal hem/fir is 12+ allowed. Are you sure that water heater is going to be a problem? Is it in the middle of that floor? Your uncle myron weighs more than that, no?
>>Your uncle myron weighs
>>Your uncle myron weighs more than that, no?
Unc Myron weighs more than 709 lbs (plus the weight of the ewater heater itself) now? Shoot, he must stayed tucked up to the table all winter this year!
How about making a small platform of 2x4s on edge to spread the load across the joists?
The water heater has a 28"
The water heater has a 28" footprint and holds 85 gallons of water. The tank weighs 124 pounds and the water calculates at about 709 pounds. Am I wrong in assuming additional support is needed?
Whoa,
Thats quite a bit of water isn't it. Does it fall near the bearing point of those joists? and what's underneath, this is a one story, no?
Say total load is 1000#
Moment = 1000*144"/4 = section modulus (sigma) * wood tension in bending
Say 1200 psi for tension in bending.
Thus sigma needs to be 51 for nominal design strength.
2 ea 2x8 s; sigma = 3* (7.25^2)/ 6 = 26.3 --- You only have 1/2 the strength needed for proper design.
My guess at the easiest fix without sistering 2 more 2x8s would be to bolt a 1/8" thick steel strap flat to the bottom of each 2x8s (sleeper). Not a simple off the top of head calculation for the bolting pattern for lateral shear between the steel and wood, a guess would be you need 5/16 lags every 3" at the ends of the 2x8s, with the bolt spacing widening to about 8" near the center span.
Why not just a jack post?
What junkhound said - but I would tack up the metal strips, shore (slightly raise/jack) the floor joists, then use countersunk wood screws alternating sides at maybe 8" o.c.
When I made my garage storage space, I had severe height restrictions on my joist material. I ended up using epoxy to attach a full length 1.5" angle steel to 2x6x20 DF. It worked out great!
If you have reasonable access
to the crawl space and can drag in a few sections of wood, I fail to see why you couldn't just double up a couple blocks on the flat and support them with concrete blocks on a footer of concrete. Place the blocks directly under the joists your water heater will be sitting on and make sure it's a tight fit by using shims to make up the last bit of space between blocking and the joists. Granted the work is a bit tough in such confined places but supporting the area from beneath would be an easy enough fix.