Second floor decking or flooring

[Leo]

At present I am ready to start second floor decking on a 16 x32  with 43"knee wall Victorias cottage.   Down in timbuktu I have been unable to locate 2x untreated decking ,it would have to be a SPECIAL order.what is available  locally is southern yellow pine 2x10 x16' at a good price of 1.32 per square foot.My joist are two 2x10 syp  with  spacers giving a finish dimension of 4.5 x9.25 on 32" centers.   My plan is to make my own tongue and groove  out of the syp 2x10s .one consideration is ripping the 2x10s in half to  about 4 and9/16  wide to reduce cupping but im not so sure this is nessasary  the joist below allow wood for some serious screws  that will be countersunked and plugged. I have even looked at a 1/4' plywood spline centered along the edges. Even if other  decking woods were available syp would be my first choice. any experience or thoughts?

[glenn kangiser]

I like your spline idea, since I make a most of my own lumber.  There wouldn't be as as much wasted as t&g would make.  I have seen local California pines shrink about 5/8" per foot of width when going from wet to dry, so dry boards would avoid future gaps (or not as large).  Narrower boards would make more but narrower gaps.

[PEG688]

 Leo  If it's fairly dry, IE under 10% moisture content with a moisture meter. And has not cupped yet you should be ok , unless your in a desert / super dry part of the world . timbuktu IIRC is quite dry.

[highlight]So again it depends [/highlight]. If your timbuktu is Az. / N.M. desert high counrty 10% will dry to be like  2 % when your in the dry and it then MTL the wood  will cup.

  Will you have wood heat in the place again making the air, then the wood, very dry.

Here in  western Wa. if we get inside MC under 10 % we are a go to use wide /wider stock . This apply's to other product as well , like floating floors etc.  

So my sumation would be rip it in 1/2 , add a dado to put a 3/8 satin ply spline into , floating spline no glue . and insure the wood is air dried or klin dry to under 10% , lower if in a super dry envir.  

 Screw and bung as you mentioned .

Good luck , photos ?   PEG  

   

[JRR]

Here's another approach:

Install the 2x10's, butted to each other ... with no dowels or other efforts to tie edges together.  Tape the joints above using reinforced fabric tape.

Then glue down a skin of plywood if the final flooring is to be carpet, ....or install tongue and groove wood finish flooring using a liberal application of glue.  Either the plywood or T&G should anchor the 2x10's together pretty well.

(The tape was just to prevent the migration of glue downward).

[John Raabe]

We did something like this several years ago in a house with an upper level T&G deck where the span was a bit bouncy (beams @ 48"). It worked quite well and greatly increased the stiffness and stability of the floor. It still looks great below and the joints stayed tight.

Use plenty of screws as well as glue.

[Leo]

Thanks for all the advice ,one thing Ive liked since the beginning is the simplicity of beams with 2x stock,simple, minimal materials,beams to hang fishing rods etc and a nice ceiling.Im want the floor finished clear possibly some honey pine stain.below i will leave it clear for the time being  but a white enamel ceiling  will be considered. The spline Idea  makes the most sense  and 3/8 sounds good for a spline originally i was going to glue one side but a snug but not tight fit seems better as to whether or not I rip them is a close call another advantage besides less shrinkage gap is any crooks will be easier to straighten.   Timbuktu is in Kentucky on lake cumberland. The plans have been great and Ive pretty  much stuck to them.Photos will be coming by early summer.  

[PEG688]

  Glad to help out    You might want to run a little chamfer on the "down side" (ceiling side )  to give it a "V" groove look.  The down side to that is once  you chamfer it you can't flip the board over so you'll be "grading your stock " as you rout the chamfer.  

 I think the floating spline will do the most for you , gives you the look both ceiling and floor you want . Will let the floor move some to expand / contract. It will align the boards for you as well , and it will reduce dust / dirt from filtering thru the ceiling.

 Looking forward to the photos    Good luck, PEG

[Billy Bob]

I think I mentioned in another thread the old factory I worked in that had SYP flooring.  Great stuff!  It was very wear resistant, and stood up to having tons of steaming woodchips dumped on it 24/6 for eight or nine months every year for nearly 100 years.

Along the lines of PEG's suggestions, would it be practical to use minimal fasteners on initial install, then pull the temp fasteners after,say, six months to a year, and tighten everything up before  final screw down and plugging?  That might allow the planks to adjust to the ambient/average moisture in the house.
Just a (maybe too dumb for words) thought.  I did this successfully with a work bench made from 2"x12" green red oak (hmmm) a few years back; got a few checks at the butts, but overall not too bad.

[Leo]

Its time to treat myself to a moisture meter.ive installed a fair amount of flooring and will let it acclimate  before instlalling .actually I see this as one of the fun parts of the project.the downstairs floor will be 3/4'txg syp from the discount floor store.building season is at hand  

[CREATIVE1]

Really showing my ignorance here, but what is "syp"?

[Leo]

creative it is southern yellow pine or long leaf pine much heavier and harder than other pines ,it is used for telephone poles,stair treads,pressure treated lumber in the old days some called it the cadillac of woods.very common in the souteast and a bargain.when clear finished it is a nice honey pine color.