Timber Framers Guild Forums General General Forum Questions 2nd Floor Construction

I am building a timber frame and am having some trouble deciding the best method for constucting my second floor. I'm OK with the timber frame, however there are a number of ways to do the second floor. Here are the options I've seen or heard of:
1. 1-1/2" T&G nailed directly to the joists and summer beams. It seems to me you'd hear every foot step from the people upstairs, not the best option.
2. 3/4" T&G and 2" EPS Foam Board. Then sheath over it. Better, but I haven't talked with anyone that has done this.
3. 3/4" T&G then lay 2x4's on end and fill cavity with fiberglass or some other insulation, then sheat over this. This seems OK too, but again no experience with it.

Could I get some opinions and options from people that have had personal experience with the 2nd floor constuction of a timber frame? Cost is always an issue. Thanks.

the 1 1/2 t&g is not too bad for sound, in my experience.
my sister built a house with a timberframe second floor deck which was hung in conventional stick framing. They then laid 1 1/2 decking and nothing else for the second floor.
They have 3 kids, and those devils can be playing fairly rough upstairs before we hear them. Footsteps above are very faint sounding,and the impact of chairs being thrown or bodies falling from the top bunk bed comes through as a dull sound, not too sharp.

I built a house for my family and used a system with 1/2" drywall, then 2x2" strapping(16" centers) with fiberglass insulation(tear 2x4 in half), then 3/4" t&g hardwood which worked as well or better than the 1 1/2".

I'm going for the 1-1/2" T&G for our second floor, but my sound concerns are limited as it's just my wife and myself.

You might want to look into a sheet material (subfloor) called "sound board". I can't remember if it's a Georgia Pacific product or one of the other manufacturers, try a Google search.

I have tried several different methods for second floor construction and have found.
1. Although good T&G will work on joist on 4'centers, dirt will work through and show in grooves below. I either put plywood down for carpet or run wood floor perpendicular to T&G.
2. To keep sound at bay, the method described above can be enhanced by adding Sound Attenuation Board or just cork between layers.
3. False floors or 2x floors are good if mechanical space is needed, but are more costly and add to second floor hieght.
4. Make sure structural frame does rest on any built up floor and bears directly to other framing.

A local timber framer told me the same thing about the dirt working through the grooves when only using 1-1/2" T&G.

Mark, can you be more specific in how you did your floor. Did you lay the sheet rock down over the 2nd floor joists and summer's, then rip 2x4's and lay them over the sheet rock (for nailers), then sheath over this with plywood or nail your finished floor right to the 2x4's?

Raph & Free State, if I were to use sound board.... would I put down 1-1/2" T&G, then the sound board, then my finished floor? Or, could I get away with using 3/4" T&G instead of the 1-1/2" T&G?

Also, is there anyone else out there with something to add?

The product I came across was a 7/8" 'Sturdi-floor' plywood that incorporated the sound attenuation board, I know it was rated a little less than the 24"+ joist spacing I needed.
So you would use whatever thickness flooring is required to make it meet or exceed code given your joist spacing.
I've never looked into the sound attenuation board as a stand alone product.

....I laid 1/2 plywood strips on the center of the joists(2" wide)
prepainted drywall went inbetween the plywood
I then screwed 2x3's in the opposite direction to the joists on 1' centers, and filled the gaps with 2x4x24 insulation, ripped in both thickness and width
then nailed down t&g.

I was initially thinking i'd screw the drywall back up to the 2x3's, but never had to, the drywall is still flat after 15yrs.

the joists were on centers that allowed me to use 24" wide strips of drywall(i.e. 26")

in wider joist spans, one might have to screw off the drywall.

Has anyone heard of putting down sheet rock in place of sound board, to dampen sound??? Someone just mentioned this to me and I'd like to get some opinions. This person saw someone doing this and was skeptical, as am I.