floor support question
- Thread starter Capt_Cully
- Start date
iamwrasseman
New member
i used four of car jacks on top of 12" solid steel plates and they worked very well and ran two 4"i beams over them i welded it all together so it was like a sled to installinto the tiny crawl space . every now and then i tighten them up and its been nine years and doing great . i was under a 18" crawl space so i couldnt even get under the tank
spartyblaze
New member
I also think the jack idea would be best - you can purchase a 2-3 quality jacks for a decent price and have the ability to keep things a bit more fluid - and adjustable if necessary.
I'd also fix the floor joist via nut and bolt to pressure treated wood to act as feet to dissipate the weight.
I'd also fix the floor joist via nut and bolt to pressure treated wood to act as feet to dissipate the weight.
Willistein
Active member
Cully, you definitely don't need to worry about frost - that is a heated space. Like Aaron said, just make sure the soil is pretty firm and you're good to go with whatever you do for support.
mr.maroonsalty
New member
No frost is getting in there, but the space is unheated and code today would have one insulate the bays, then freeze might get in; that would depend on grade. I think it would be easiest to stick build a header with triple 2x6 posts and 2x10 header, much like what looks to be going on on the drywall side. Lally posts are easy to cut; I'd at least price using them..
Capt_Cully
Active member
Not sure what Lally posts are? Wouldn't all of that require some sort of foundation or solid footing? Bringing me right back to where I started? I guess I should call my buddy who's a contractor/builder....
I was hoping for an easier solution. Something I could grab at Lowes or HD......
I was hoping for an easier solution. Something I could grab at Lowes or HD......
Willistein
Active member
lally posts are just those round metal posts (at Lowes) that have a screw jack on top. This is pretty simple - doesn't need to be complicated. Couple of beams supported by a couple of lallys (if you want to be able to jack it up a bit) and a couple concrete deck supports. dig down a little, use a little crushed stone, all set.
mr.maroonsalty
New member
they needn't even the screw jack; all you need is the concrete filled post, a carborundum metal cutting blade for a circular saw, and the top and bottom plates. They are a wee bit easier using building from the ground up, but should be do-able for a tight install. My first instinct would tell me to go for a pair of 12-16" pt 2x6's and building a triple post.
iamwrasseman
New member
hey mark if you use jack posts i can shorten them for you pretty quickly just let me know and we can do some measuring .
Capt_Cully
Active member
HD has the extending ones that would fit down there. Something like 36-60 inches. So that wouldn't be an issue. I think across a 4 foot span there are a couple of different ways to do the header. 2x6s bolted together. Pressure treated 6x6s. Etc.
I'm still stuck on the footing. You guys are saying its ok to go with the deck footings from HD? Should I bury them down?
Do you think I should hang a reference line? Is it worth while to hang a piece of chalk line from the two main supports on either side of the crawl space? That would let me know if the posts or joists needed adjusting because of the ground settling.
I'm still stuck on the footing. You guys are saying its ok to go with the deck footings from HD? Should I bury them down?
Do you think I should hang a reference line? Is it worth while to hang a piece of chalk line from the two main supports on either side of the crawl space? That would let me know if the posts or joists needed adjusting because of the ground settling.
Settleing really shouldn't be an issue.Your pics showing the unwrapped water lines and heat duct are pretty good indicators its not going below freezing.That was or would be the biggest concern.
2 adjustable jack posts ,a 2x6 header or 6x6 and some deck footings are more than adequate,imo.
2 adjustable jack posts ,a 2x6 header or 6x6 and some deck footings are more than adequate,imo.
I think you have it Cully. As I understand it, for the beam to be across the joists it will be in the 4' dimension of the tank, so only one beam would be needed, directly beneath the tank.
Doubled 2x8s (nail them together so they act as one) would be more than enough for that beam. 6x6 would just be heavy and difficult and not really necessary.
definitly no frost footing needed, as others have said. Solid base is the key. Burying is not necessary, unless the stone doesn't compact well = dig down to firm soil, or the ground is mushy = use the method with the fabric in my original post.
Don't stress out about it too much, if you figure your whole tank weights 2500lbs, and the entire weight is supported by this setup (which it isn't, some of the tributary load transfers along the joists to the other supports), the deck blocks are only putting about 8.5 PSI on the ground. A 250 lb person on a bike does more damage than that!
Doubled 2x8s (nail them together so they act as one) would be more than enough for that beam. 6x6 would just be heavy and difficult and not really necessary.
definitly no frost footing needed, as others have said. Solid base is the key. Burying is not necessary, unless the stone doesn't compact well = dig down to firm soil, or the ground is mushy = use the method with the fabric in my original post.
Don't stress out about it too much, if you figure your whole tank weights 2500lbs, and the entire weight is supported by this setup (which it isn't, some of the tributary load transfers along the joists to the other supports), the deck blocks are only putting about 8.5 PSI on the ground. A 250 lb person on a bike does more damage than that!
Capt_Cully
Active member
So if I'm comprehending this properly, I merely need to brace the pressure point created across the construct of the floor, not necessarily the entire footprint of the tank.
2 bases, yet to be determined, one cross beam of 2, 2x8's bolted together.
I'm an overkill kind of guy which is why I used 4 poles on my 6 foot 180.
I'm thinking I'll to a 6 foot beam, spanning the joists below the 4 foot length of the tank, on center, with the 2 support poles 4 feet apart, just below the tank itself, again, on center with the 3 foot width.
Sound about right fellas?
2 bases, yet to be determined, one cross beam of 2, 2x8's bolted together.
I'm an overkill kind of guy which is why I used 4 poles on my 6 foot 180.
I'm thinking I'll to a 6 foot beam, spanning the joists below the 4 foot length of the tank, on center, with the 2 support poles 4 feet apart, just below the tank itself, again, on center with the 3 foot width.
Sound about right fellas?
Capt_Cully
Active member
OK, I like it. Do 2x8's need to be pressure treated or anything special?
I'm heading down to dig a bit, see what's under the crush.
I'm heading down to dig a bit, see what's under the crush.
no they dont need to be pressure T.
Forgot ,if your building that header yourself,dont forget to check the crowns.Orient them the same before gluing and nailing together.
If your not sure just eye down the length on the small side of the 2x8's ,you'll notice a bow up or down.
Installed with your jacks,you'll want the crown up.It'll settle on its own from the weight above.
If you doit the opposite it would mean your floor above would have to sag before it would touch the center.Hope that make sense.
Forgot ,if your building that header yourself,dont forget to check the crowns.Orient them the same before gluing and nailing together.
If your not sure just eye down the length on the small side of the 2x8's ,you'll notice a bow up or down.
Installed with your jacks,you'll want the crown up.It'll settle on its own from the weight above.
If you doit the opposite it would mean your floor above would have to sag before it would touch the center.Hope that make sense.
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Capt_Cully
Active member
Here's entrance to crawl space, doors on right are what's on the otherside of the wall on the right when looking down the crawl space above.
Dug down about 4-5 inches. The crush is super compact. Then I hit solid clay earth. Our area is known for bedrock and clay earth. I honestly think I'm gonna be fine with either lifting plates as bases, or some other metal plating that will enlarge the footprint.
Any of you builders or engineers see any problems with my thinking?
I'm sorry to belabor these points, but, nervous guy + new home + 3000lbs of salt water tub in new living room...etc..etc...
Dug down about 4-5 inches. The crush is super compact. Then I hit solid clay earth. Our area is known for bedrock and clay earth. I honestly think I'm gonna be fine with either lifting plates as bases, or some other metal plating that will enlarge the footprint.
Any of you builders or engineers see any problems with my thinking?
I'm sorry to belabor these points, but, nervous guy + new home + 3000lbs of salt water tub in new living room...etc..etc...
Capt_Cully
Active member
Oh and height of space is 45". Joists are 16" on center, apart.
