Ideas for finishing Sunroom.

[coldsolderjoint]

I have been using my sun-room for a storage area/workshop/disaster space since we moved into the house, its now in the project queue. I wanted to put up some pictures here and get some ideas on finishing it before we get that close to doing it. It is about 10x12, and has only jalousy storm windows on it. Currently not heated nor insulated. It has a concrete slab, and a cinderblock foundation up to about waist level and then is wood framed. I'm thinking about turning it into a laundry area and storage. I want to remove the 4 windows on the long side and use that space for wall mounted cabinets for storage and a workbench area. I will do all the work myself.

Here are some of the major concerns I have now.

I want to insulate and heat it. Insulating the ceiling should be pretty easy. I can remove the thin paneling on the ceiling and insulate from below more easily than from above I believe.

Walls.. I was thinking to "fur" them out and put fiberglass batts in the window areas, I'm not sure how I would insulate the lower part where the cinder block is.

Floor.. Should I insulate the slab with something like foam and install plywood on top of it?

Heating.. I was initially thinking electric baseboards, they can be set to a much lower temperature than the house pretty much to just prevent freezing of the pipes, however, on the other side of the wall, I do have hot water baseboards which I could tap into. It is a single loop however.

I'm sure I will have about 1000 more questions on ideas, but I figured I would take some raw.. cluttered pictures to ask you guys for some ideas to throw at me.

Thanks in advance.

 

[coldsolderjoint]

heres two more

 

[Sponsor]

 

[Dana]

To insulate the cinder block, glue at least an inch of rigid foam board (EPS is cheapest) to the wall with blobs of foam-board construction adhesive and seal the seams with duct-mastic. If you put at least 3" (R12.5) of foam on the wall you can then install furring TapConned through the foam to the cinder block 24" o.c. (for minimal thermal bridging) on which to hang the gypsum, and it would perform about the same as R19s in 2x6 framing.

If you furred out the existing framing to the same plane as the cinder block, caulk the studs & plates to the sheathing, and install batts insulation in the cavities, taking care to tuck every corner and edge, then tug back so that the interior side of the batt is just proud of the furring. (Be sure to caulk the bottom stud plate to the cinder block too, and between doubled-up top plates, and use can-foam to seal any stud or sheathing penetrations by wires/plumbing,etc.) The batt has to be thick enough that it's a compression fit though, or it won't perform to spec due to free-flowing convection in the gaps. A compressed batt won't hit it's labeled number, but it will have a higher R/inch of thickness when compressed to a higher density. (An R19 batt designed for 2x6 is the same amount of fiber as an R13. The R19 is measured at about 6" loft, and when compressed into a 5.5" stud bay it performs at only R18, or R3.27/inch. But compressed into a 3.5" stud bay it runs R13, which is R3.71/inch.)

Alternatively you could install a layer of housewrap or tautly-stretched landscaping mesh in the interior side of the furring and either blow if full of cellulose, THEN put the interior-side foam up. If you want to take up less interior space, use 1" of EPS against the cinder-block, and 1" of foil-faced polyiso on the interior, taping the seams with 2" FSK tape (foil duct tape).

In a NJ climate it's cost effective to put up to 1.5" of EPS (and not polyiso), which can retain moisture if you're not careful) on the slab, and TapCon half-inch OSB sheathing as a sub-floor, even if the slab isn't heated. If it's going to be a radiant floor, bump that to 2.5-3". Be sure to put a layer of 6mil polyethylene between the concrete and foam as a ground vapor retarder and slip surface, and stagger the seams of the foam with those of the subflooring to keep it from compressing at the foam-edges. It's best to use a t & g sheathing to avoid the "potato-chip curl" on the subfloor with seasonal room humidity changes. Spacing the TapCons 24" is fine with t & g , but you'd have to tack all the corners if using ship-lap or flat edges sheathing.

As long as that attic space is vented and you religiously seal all the ceiling penetrations (avoid recessed can lighting if possible) you can blow cellulose in there, which will outperform any low-density batt solution at equivalent depth. If you don't have at least 2x12 joists in there it could be tough meeting code at the eaves. You need to keep at least a 1" clearance from the roof deck to the fiber insulation, and you need at least 11" of fiber insulation to hit the code-min R38. Venting the attic space at the ends instead of at the eaves gives you a bit more insulation space, and if need be you can use 4" of EPS (R15 minimum to meet IRC spec, but if you only have 10" to play with 3" of foam would be fine) against the roof deck in those tight sections, sealing the edges with can-foam to avoid transporting moisture to the roof deck via convection, at which point it's fine to fill in under the EPS with fiber insulation.

When installing /re-installing windows be sure to flash the rough opening so that it laps properly to the housewrap or felt, and use backer-rod + can-foam to air-seal it, then stuff as much fiber insulation in the mini-gaps to where it had good resistance and spring when pushed with a finger.

Take the time to really air-seal at every layer in the stackups- it's the cheapest thermal performance you can buy, and really makes a difference in energy use, comfort, and resilience to moisture. As much fuss as people make about vapor barriers, far more moisture gets into wall assemblies from air movement than vapor diffusion. In your climate you don't NEED (or particularly want) vapor barriers in the stackup (even though foil facers are powerful vapor barriers)- if you make it air tight it will be more resilient. Code doesn't require vapor barriers no matter what the stackup you have in your climate zone, and if you have vinyl siding (which it appears you do) the back-vented siding gives the assembly quite a bit of capacity to dry toward the exterior.

 

[coldsolderjoint]

Thanks Dana! I didn't see this post. (I've been busy and set the notification type incorrectly).

A lot of information to digest!

I have to get out there and make some drawings with what kind of clearance I have on the walls and Windows to figure out how thick I'm going to put the insulation on.

The Ceiling joists are only 2x4's so I guess this will be a "best you can do" sort of job.

I think I'm shying away from the hydronic heat and go with an in-wall electric model such as this one: http://www.homedepot.com/p/Fahrenheat-1500-Watt-Small-Fan-Forced-Wall-heater-FFH1612/100160605#

It just seems a lot easier to just drop a new wire in and go from there.

In continuing discussions with my wife, she would be happy if the floor was finished with simply a new coat of epoxy style paint. Is there someway to calculate the efficiency differences between the foam and sheathing, and say a cheap laminate or vinyl vs Uninsulated? Being this will be a laundry room however, I'm kind of thinking she won't want to be putting on shoes or slippers every time she goes out there.