[neolitic]

Dunno 'bout the front range,
I couldn't figure out your footing
on a bet.
I've done it, plans approved, built,
inspected, accepted, and occupied.
Several times over. Would do it again.
Apparently you wouldn't, and maybe can't.
I wouldn't even audition to play a
Colorado code expert on TV! :laughing:

 

[K2]

Dunno 'bout the front range,
I couldn't figure out your footing
on a bet.
I've done it, plans approved, built,
inspected, accepted, and occupied.
Several times over. Would do it again.
Apparently you wouldn't, and maybe can't.
I wouldn't even audition to play a
Colorado code expert on TV! :laughing:

Yeah, we have some weird stuff including but not limited to our floating walls. Makes it easier for ghosts to move from room to room. :laughing:

 

[bob_cntrctr]

Ok, does it need to be vented and how do you vent it??

"Need" as in "code" - don't know. Or as in "really should", ya. Moisture will come up through the concrete slab and get trapped there.

Traditional sleeper floor, they used to just lay 2x4's out on the concrete floor. Then everyone would be surprised when the floor rotted out ten years later.

But you can make it work with a few updates. First, sit the sleepers on sill plate gasket for thermal break and moisture barrier.

Next, think about DriCore sub-flooring. It's just OSB on a million little plastic sleepers - and here's what they recommend:

...We recommend that the panels have a 1/4" space away from all perimeter walls and room obstacles, such as support posts or stairs, to allow for airflow ...

...Vent cover installation for increased airflow Increasing air flow under DRIcore panels can be accomplished easily by installing vent cover openings into the finished flooring and DRIcore panels every 10’ around exterior perimeter walls. De-humidification and proper mechanical air handling systems will help ensure continued air flow for moisture and humidity reduction. To finish off, install a low profile vent cover and inspect periodically....

In other words, treat the space under the floor as a space to actively keep ventilated.

I once worked on a place where all the wall cavities had been treated like this - very interesting construction.

 

[neolitic]

.....
Next, think about DriCore sub-flooring. It's just OSB on a million little plastic sleepers - and here's what they recommend:.....
I once worked on a place where all the wall cavities had been treated like this - very interesting construction.

DriCore is installed directly on the slab....
it has no bearing on the OP's situation.
As to the floor system that
"rotted out ten years later.."
Obviously, you need to look up vapor barrier
when you purchase your next do it yourself manual.
I can't imagine what you think would be accomplished
by using sill seal gaskets under treated sleepers
laying on 6 mil vapor barrier.
Actually I can't imagine what you're thinking...period.
(Same advice as before, Find someone who has a clue.)

 

[dlcj]

ok there a millon ways to do this job but from the start i was thinking the same thing as pknyrayn before i read his. Build the floor as a normal floor only lay down a 6 mil vapor barrior first ,maybe glue it to concrete around edge. dont know what your span is but 2x8 or 2x10 joist with 2x10 rim and flush center girder. only shim the rim and center girder where needed. you'll need to use a transit or builders level to draw a line arround walls and reference that to the house floor or just measure down from ceiling but dont assume the concrete is level. The concrete was designed to hold a car with 1000 lbs per wheel point loads itil hold a floor.

 

[bob_cntrctr]

DriCore is installed directly on the slab....it has no bearing on the OP's situation.

OP: "Can I just lay my floor joist directly on the concrete?"

Which OP did you read?

As to the floor system that "rotted out ten years later.." Obviously, you need to look up vapor barrier when you purchase your next do it yourself manual.

My Post: Traditional sleeper floor, they used to just lay 2x4's out on the concrete floor. Then everyone would be surprised when the floor rotted out ten years later.

I can't imagine what you think would be accomplished by using sill seal gaskets under treated sleepers

My Post: sit the sleepers on sill plate gasket for thermal break

Tell ya what, I'll read up on vapour barrier if you study this website:
readingcomprehension dot com
Helps students master specific reading skills: main idea, factual recall, vocabulary, sequence, inference, and drawing conclusions.

:thumbsup::lol::laughing::lol::laughing:

 

[BuiltByMAC]

I would like the floor to match the same height as my exisiting floor inside my house. This would require me to raise the floor off the cement garage floor. I have to raise it about 10 inches.

Next, think about DriCore sub-flooring. It's just OSB on a million little plastic sleepers - and here's what they recommend:

OP: "Can I just lay my floor joist directly on the concrete?"

Which OP did you read?

OSB with a million little sleepers placed directly on concrete would put garage subfloor 9" below the rest of the OP's house flooring - he specifically stated he wanted the floor at the same level. That's why it has no bearing in this thread... that, and you'd need a perfectly level garage floor. I've seen many that are and some that aren't.

Mac

 

[bob_cntrctr]

OSB with a million little sleepers placed directly on concrete would put garage subfloor 9" below the rest of the OP's house flooring - he specifically stated he wanted the floor at the same level. That's why it has no bearing in this thread... that, and you'd need a perfectly level garage floor. I've seen many that are and some that aren't.

Mac

Next, think about DriCore sub-flooring. It's just OSB on a million little plastic sleepers - and here's what they recommend:

...We recommend that the panels have a 1/4" space away from all perimeter walls and room obstacles, such as support posts or stairs, to allow for airflow ...

...Vent cover installation for increased airflow Increasing air flow under DRIcore panels can be accomplished easily by installing vent cover openings into the finished flooring and DRIcore panels every 10’ around exterior perimeter walls. De-humidification and proper mechanical air handling systems will help ensure continued air flow for moisture and humidity reduction. To finish off, install a low profile vent cover and inspect periodically....

In other words, treat the space under the floor as a space to actively keep ventilated.

That is - when you enclose a space over a concrete floor with DriCore, the company recommends taking positive steps to ensure ventilation under the floor to avoid moisture problems. What did a number of posts inthis thread allude to? Problems in the enclosed space under this guy's theoretical sleeper floor. Soooooooo - take a lesson from DriCore - "treat the space under the floor as a space to actively keep ventilated"

Sheesh.

 

[Basement Water]

You're definitely going to want to protect the floor joists from moisture somehow. Even if you don't have actual pools of water on the concrete, it absorbs water from the ground below it like a sponge and releases the water vapor into the air. You probably won't see the moisture because it dries the second it hits the air, like water in a potted plant, but if you lay wood directly on it, it's going to collect on it, rot, grow mold and become a habitat for insects.

Hi,

I am a painter by trade but would like to add a room to the back of my garage. I would like the floor to match the same height as my exisiting floor inside my house. This would require me to raise the floor off the cement garage floor. I have to raise it about 10 inches. Can I just lay my floor joist directly on the concrete?

 

[neolitic]

That is why everyone with any
experience has said to start
with a vapor barrier!

 

[K2]

Sounds like the IRC needs to address this specific type of construction and set some standards..... or specifically disallow it , my choice being the latter.

 

[neolitic]

How is it any worse than burying everything
in concrete?
If something happened to the mechanicals,
what is more accessible? Bust up concrete?
Pull up a sheet of plywood?
I'm having trouble seeing your objection here.
It's not my first choice, but it has proven
a good solution to a fairly common "I need more
living space." problem.

 

[K2]

1) I would like to see an IRC standard.
2) Slabs and clean fill are inorganic i.e. can't grow mold.
3)A slight waste plumbing leak under a closed wood floor could go undetected for years. Under a slab a slight waste leak is likely to seal itself and would be unlikely to affect the living area.
4) I'm not that crazy about living space over pressure treat anyway. The lateset PT has not been around long enough to know of any chemical concerns in an enclosed area.

Not really arguing because I've done these wood over slabs myself. Just throwing out ideas.

As I already mentioned, in most areas with frost protection, digging a crawler for this type of construction would be very simple because a skidder can go through the garage door.

 

[dlcj]

[Q digging a crawler for this type of construction would be very simple because a skidder can go through the garage door.[/QUOTE]

and you end up with a shallow indoor swimming pool ( probably lower than grade. dont know havent seen the site) under the floor. Major work to water proof that or keep it drained if the yard is not graded right. Not worth it. Just lay the vapor barrior and not treated joist on treated shims! If it needs to be vented ( my opp. it dont) just some screened crawl space vents cut in to the out side will work.:thumbsup:

 

[drbrsjr]

Joist System

K2, I am doing the same thing. A 22x25 garage into a family room that I have to raise the floor about 20 inches. After I break up the garage floor and dig down to get the 36" depth requirement by code, what system do you recommend for the floor joists? Should I just dig holes and build it like a big deck with 4x4's supporting 10" beams and 8" floor joists. Any ledger boards would be attached to the garage wall studs. Would that be strong enough if I had a center carrier beam in the middle of the garage? Or, should I build a wall inside the garage wall on each side and one in the middle and set the 8" PT boards on the concrete walls? Any help would be appreciated.

I would think that R408.1 would apply.

I'm not doing anything I'm just questioning whether a "sleeper floor" is allowed under the IRC or the UBC..

I would say that i could not get a sleeper floor approved in my county for a number of different reasons including R408.1.

For my area with 36"min stem walls it would be easy to get a skid into a garage for a half a day and dig a proper accessable, (irc R408.3) crawl space in about 4 hours and then do a joist system. Or the slab over that i already mentioned.

 

[nbishop]

Use of PT wood indoors

Found this on another webite but i cant post the link cause im new

Indoor Use of Treated Wood
Pentachlorophenol treated wood should not be used in residential, industrial or commercial building interiors, except in laminated beams or building components that contact the ground and are subject to decay or insect infestation. When used for such purposes, pentachlorophenol treated wood must be covered with two coats of an appropriate sealer such as urethane, shellac, latex epoxy enamel or varnish.
The EPA has advised that creosote treated wood should not be used in residential building interiors. Creosote treated wood in interiors of industrial buildings should be used only for wood block flooring and for industrial building components that contact the soil and are subject ot decay or insect infestation. Such industrial application is acceptable, provided that two coats of an appropriate sealer are applied. For creosote treated wood block floaring, coal tar pitch and coal tar pitch emulsion are effective sealers. Urethane, epoxy and shellac are appropriate sealers for creosote treated wood when used other than as wood block flooring It is believed that limited interior uses of appropriately sealed pentachlorophenol and creosote treated wood will not cause unreasonable adverse effects to humans or the environment.
EPA has not advised against the interior use of arsenical treated wood because the arsenic air levels measured in homes constructed with this type of treated wood are not significantly different from background arsenic air levels when dust has been vacuumed from the wood surface. Therefore, wood that is pressure-treated with water-borned arsenical preservations may be used inside residences wtihout a sealer, providing that all machined sawdust is vacuumed from the wood surface.

Just thought this info might interest some of you.

 

[neolitic]

Found this on another webite but i cant post the link cause im new

Indoor Use of Treated Wood
Pentachlorophenol treated wood should not be used in residential, industrial or commercial building interiors, except in laminated beams or building components that contact the ground and are subject to decay or insect infestation. When used for such purposes, pentachlorophenol treated wood must be covered with two coats of an appropriate sealer such as urethane, shellac, latex epoxy enamel or varnish.
The EPA has advised that creosote treated wood should not be used in residential building interiors. Creosote treated wood in interiors of industrial buildings should be used only for wood block flooring and for industrial building components that contact the soil and are subject ot decay or insect infestation. Such industrial application is acceptable, provided that two coats of an appropriate sealer are applied. For creosote treated wood block floaring, coal tar pitch and coal tar pitch emulsion are effective sealers. Urethane, epoxy and shellac are appropriate sealers for creosote treated wood when used other than as wood block flooring It is believed that limited interior uses of appropriately sealed pentachlorophenol and creosote treated wood will not cause unreasonable adverse effects to humans or the environment.
EPA has not advised against the interior use of arsenical treated wood because the arsenic air levels measured in homes constructed with this type of treated wood are not significantly different from background arsenic air levels when dust has been vacuumed from the wood surface. Therefore, wood that is pressure-treated with water-borned arsenical preservations may be used inside residences wtihout a sealer, providing that all machined sawdust is vacuumed from the wood surface.

Just thought this info might interest some of you.

That was pretty useful information
25 years ago.
The only place you will commonly see
penta treated wood is power poles.
Creosote is pretty much confined to
railroad ties.
The stuff at your lumberyard or
B Box is safe to use indoors.

 

[nywoodwizard]

This post is a bit old ,wonder if it ever finished. He's probably in a retirement home by now.:wheelchair:

 

[K2]

K2, I am doing the same thing. A 22x25 garage into a family room that I have to raise the floor about 20 inches. After I break up the garage floor and dig down to get the 36" depth requirement by code, what system do you recommend for the floor joists? Should I just dig holes and build it like a big deck with 4x4's supporting 10" beams and 8" floor joists. Any ledger boards would be attached to the garage wall studs. Would that be strong enough if I had a center carrier beam in the middle of the garage? Or, should I build a wall inside the garage wall on each side and one in the middle and set the 8" PT boards on the concrete walls? Any help would be appreciated.

Oh sorry, I missed this post. I didn't think anyone reads my posts. If you're still around I would tell you how I would do it in my area.

 

[drbrsjr]

New living space

K2, I'm still around. I was planning on digging out my garage floor for access to the mechanicals but it doesn't seem to be a very popular idea. I was concerned about screwing in a ledger on the existing garage 2x4 walls for the floor joist to sit on. It doesn't seem sturdy enough to me. I thought I might build a wall inside the existing garage wall or build up the floor on posts on top of footers and beams like I would build a deck. I want to run heat runs out to the new additional living space and water/drains as well. I have also been told that I need a 36'' crawl space by code in my area. Any advice? Thanks from Columbus Ohio.