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Old 10-29-2009, 03:57 PM   #1
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Hello!

Been reading here for a little, first time posting!

I have a house which was never completed... it has two unfinished rooms they basically "walled off" by putting a closet infront of them (no idea why) the houe was built in 1996 so it made no sense... but anyways... I wanted to finish these rooms at least get a floor in them right now they have just a few pieces of OSB and plywood laying on the joists in the one room.. i wanted to at least have it subfloored so we can at least safely store stuff in it without having to fall throug the cieling... the room isnt small either... its 20x18 ft..

my question is.. so in pennsylvania do you need a building permit to lay subfloor? if so what exactly do I tell them I am doing and do they have to inspect subfloor? I mean it seems simple enough to do... I've done some construction work but never on this level (simple stuff.. molding...doors etc)..

the joists are 2x10's and are 16 inches on center so its a pretty standard install... there is blown insulation right now on the floor since its unfinished to insulate it...

what would you guys suggest to do for the sub floor? does the insulation need removed? the cieling isnt insulated at this point and we just want some storage space.. also what is better for subfloor? our whole house was built with OSB from the looks of it as the flooring... would you go toung and groove OSB or plywood? thanks!

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Old 10-29-2009, 05:28 PM   #2
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1. You need a permit if the local code enforcement official says you need a permit. Ask them.

2. I am not clear from your post what is holding up the insulation. You said there are a few pieces of OSB on the floor, from that I assumed most of the floor was open joists, so I don't get it, what is keeping the insulation from falling through the joists into the basement?

3. OSB is fine for subfloor, personally I prefer plywood, but the industry assures us that OSB is just as good. If you think you might tile the floor eventually, you should plan on two layers of subfloor, but you could always add a second layer later.

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Old 10-29-2009, 05:44 PM   #3
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Just a suggestion--If you are planing to turn the room into living space in the future--

SCREW the sub floor down-when the room is being remodeled the flooring will have to be removed to

install heat ducts,electrical and all the rest.

I am with HOLZMAN,Plywood makes a better sub floor than OSB.--MIKE-
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Old 10-29-2009, 06:49 PM   #4
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whoops, sorry I should of said this was a second floor room. that completly slipped my mind. the room below is completely finished so right now the drywall is what is holding the blow in fill up there. out of the 4 rooms on the second floor only 2 of them where finished, the other two are just joists and 2x4 walls no drywall, and nothing is finished except they have electrical going into them and a single light on a switch, besides that its basically left for us to finish

thanks for the advice so far!
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Old 10-29-2009, 06:49 PM   #5
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I third for the plywood. Interesting read on wall OSB: http://www.rci-online.org/interface/...ton-murphy.pdf
Be safe, Gary
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Old 10-29-2009, 07:28 PM   #6
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As Mike stated above, make sure you have the appropriate HVAC as well as electrical in place. If it is going to be a living space, then there are lots of rules that apply.
Do you have pictures?

PS-YES plywood-preferably tongue and groove!
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Old 10-30-2009, 02:07 PM   #7
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yeah plywood sounds best, might cost a tiny bit more but seems the best choice.. I'd assume the standard is still 3/4" plywood with an adhesive bead running down the joist (if its permanent sub flooring) screw wise what would you recommend? 2 1/2" phillips flat head screws or a T-25 torx head screws? (i'd assume torx screws dont strip as fast as phillips)
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Old 10-30-2009, 09:04 PM   #8
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If there is a chance of moisture such as from spills and the like I would suggest looking at a product called Advan Tech. It has a 50 yr warranty.
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Old 10-31-2009, 07:19 PM   #9
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Hidden rooms? That's just weird. Was there any reason given? Is there any indication (nail holes in studs) that the rooms were finished at one time? Did you know about the rooms when you bought the house?
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Old 10-31-2009, 10:50 PM   #10
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"Bonus rooms"--They are fairly common,I've finished up a couple of them.
Biggest hassle is the heat/air-The last one I did the furnace was not sized for the extra room.

We got the hvac man to get it to work ,but it was expensive.
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Old 11-02-2009, 10:04 AM   #11
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Quote:
Originally Posted by zpm View Post
Hidden rooms? That's just weird. Was there any reason given? Is there any indication (nail holes in studs) that the rooms were finished at one time? Did you know about the rooms when you bought the house?

Oh yeah the real estate person even pointed them out, they are on the house blueprints and everything (we fortinuatly got a copy of them with the house)

no signs they where ever finished, no nail holes or anything, just unfinished construction... this house is wierd to the point we have a staircase that goes up in a L shape but has no railing down the side but at the bottom it has a rail up 3 ft and at the top the hallway has railing on the side but for some reason they never railed up the stairs... so its a 10 ft drop at the top if you trip... (yet another project to do!)

so i think they ran out of money when building the house and took a lot of short cuts to keep stuff from being finished
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Old 11-23-2009, 08:53 AM   #12
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Well ran into a problem.... the unfinished room's floor has a span of 29 ft. right now they have two sets of ~18 ft long 2x6's as the joists... which seems way too big of a span for 2x6's... the entire rest of the house was done with 2x10's... why in the world they did 2x6 in this room I will never know (probably since they knew it wasn't going to be finished due to money they "saved" money by using 2x6 ugh)

any idea on how I can fix this? could I somehow sister up 2x10's? or is it possible to build another floor perpendicular to the joists with 2x4's to make it higher? right now this set of joists are 4 inches below the floor of the rest of the house which I should of caught to start with....

below this on the 1st floor there is a wall going down near center of the joists...

attached is a floor plan of this small section of the house where the room above on the 2nd floor is unfinished... this is the 1st floor's plan and I drew the joists above in red to show the direction (not to scale)

Floor Plan Image: http://www.diychatroom.com/members/b...2427-1stfloor/

any idea's? I'm thinking I need a structural engineer... but looking for ideas first to give myself an estimate of the cost and if I want to do this or not right now... thanks!

Last edited by BlueBSH; 11-23-2009 at 08:56 AM.
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Old 11-23-2009, 10:36 AM   #13
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Those 2x6 joists are only about half the strength they need to be, so you are correct about the undersizing. The required size depends on the psf code required loading of the floor, where I live it would be 30 psf live load for a sleeping area, 40 psf live load if a living area, plus dead load.

You did not mention if the joists are 16" oc, I assume they are. By MA tables, 2x6 @16" OC using 1.5 million modulus on a living (not sleeping) area is good for 9'6" span. So you have a few options to consider. One is to double the joists, which may be feasible if you have good access. A second option is to replace the joists with the proper size ones. Building up the joists using perpendicular structural elements is likely not feasible, due to the difficulty getting a good enough connection between the two framing systems.

You may be able to bolt on steel plates to the side of the joists, this effectively converts the joists into flitch beams. Not very common, but it could work here. Very difficult to attach a 2x4 to the top of each joist and get adequate attachment to mobilize the strength of the composite beam, but you might discuss that option with your structural engineer.
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Old 11-23-2009, 10:49 AM   #14
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Just throwing an idea out there, but would it be possible to put a second set of joists 2x10s in the middle of the existing joists? so we'd have a 2x10 joist in the center of the current empty space created by the 16inch spacing of the 2x6's? and virtually create a new joist system independent of the existing one?

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