John Sayers' Recording Studio Design Forum Archive

wow its a hornets nest in here. This looks like a ton of work man. Good luck

cadesignr wrote:what do you have to do to the existing roof support(trusses?) to support this kind of weight . . .

Great question, and one that I haven't had time or context to post the answer to yet. I was going to get the floor situation squared away before detailing that for everyone.

Basically, I plan to rip off all the existing ceiling, remove the hat channel, and then lay new 2x6 joists 16" o.c., parallel to the existing trusses, which would move all of the ceiling weight off of the trusses and transfer it to the outer leaf walls. I ran the calc's and it seems OK for my 10' + headers span. Here's a terrible illustration of this. (I suck at Photoshop.)

Ballgame wrote:wow its a hornets nest in here.

You must have mistaken the buzzing sound for hornets, Ballgame -- that's my brain frying!

This looks like a ton of work man.

Actually, according to my abacus, it's probably more like 35 tons!

Good luck

Yeah, I'm going to need it! Of course, this isn't etched in stone yet... I'm just trying to wrap my head around the possibility of doing this.

Scary indeed!

sharward wrote: I ran the calc's, and it seems OK for my 10' + headers span.

Shar,

That looked weird to me - so I went to look into it -

According to the Western Lumber Product Use Manual- which is published by the Western Woods Product Association (WWPA) - the value for Fb with DF-Larch #2 is not 1345.5psi but is rather 900psi

If you wish to see this for yourself - you can at

http://www.wwpa.org/_techguide/pdf/A.pdf

But you will have to register first.

I would also point out that I get nervous about the minimum bearing they note in the table.

I']ll take a look at this again tomorrow - but 2x6 @ 16" oc for a 10' span with that load makes me tense........ just a gut feeling - but i always follow my gut.......

Sincerely,

Rod

rod gervais wrote:According to the Western Lumber Product Use Manual- which is published by the Western Woods Product Association (WWPA) - the value for Fb with DF-Larch #2 is not 1345.5psi but is rather 900psi

If you wish to see this for yourself - you can at

http://www.wwpa.org/_techguide/pdf/A.pdf

Wow! You're right! There it is, at the top of page 6! (Right?)

But you will have to register first.

Nope... It let me right in. (I just acted natural and didn't make eye contact with the guard. )

I would also point out that I get nervous about the minimum bearing they note in the table.

Sheesh -- I thought I had found the coolest little span calculator, and now you're shooting holes all over it! What the heck? "with a minimum bearing length of 0.32 in. required at each end of the member"? 0.32 inches? Are they nuts? My index finger isn't even that thick!

Rod, do you know of any other span calculators on the 'Net for us construction idiots -- hopefully ones we can rely on? I tried to learn how to use the span tables, but I'm afraid I just don't "get it."

I'll take a look at this again tomorrow - but 2x6 @ 16" oc for a 10' span with that load makes me tense........ just a gut feeling - but i always follow my gut.......

FYI, I have no objection to upping the ante to 2x8, as long as I have the clearance where the roof sheathing gets really close to the top plates on the east wall (direction of photo). I have not measured this yet -- my attic photos were taken from the hatch in the laundry room with just my head and shoulders inside. I admit it: I'm "atticphobic."

Changing my spacing to 12" o.c. is also an option.

I should also confess that I'm assuming that "Douglas Fir - Larch" is what I have available in my region. I suppose a field trip to Home Depot is in order.

Thank you so much, Rod. I'm so appreciative that you've "got my back" on this.

Another day, another life saved by Rod

Dammit, i was just at home depot getting prices. And i checked the tag, and it only said Doug Fir. Now i know what stamp to look for to see if it is Larch ... it makes a big difference, like a foot of span or something. That is a great PDF Rod, i'm so glad you put that link there.

BUT ... checking the span tables (40# total load) in that PDF, Doug Fir larch #2 at 16 OC says 10'9", not that far off from what the "internet calculator" predicted. which is comforting. although it's a heck of a lot MORE comforting to have span tables put out by a trusted source

by the way, 2x6x10 are $5.40, and 2x8x10 are $7.27 at my home depot. in case that helps (not that you'd cut costs here, mind you ) ... there is no reason NOT to overkill here where life is at stake of course, especially for a few dollars. i just put that for the curious.

i might also add that 2x10x10s are $9.98 and 2x12x10s are $11.85 ... just in case you want to be REALLY safe!

[EDITED TO ADD DOLLAR SIGNS ... ]

it should be ok to taper the tops of the joists at the end where they have to fit into the narrow space between the wall top plate and the roof sheathing, i'm guessing. you'd have to do this with either 2x6 OR 2x8. will this affect the strength of the member very much or at all?

roughly, i think 2x6 wood is 2 lbs/foot and each sq foot of 5/8 gypsum is about 2.3 lbs, so even if you did 5 layers of gyp aren't we talking under 15 psf or so, so isn't 40 pounds load capacity plenty ... that leaves 25 psf live load ... which should be enough for a ceiling below an attic space right?

or am i thinking about this all wrong, totally misunderstanding how this works?

i guess i need to read that pdf, which i will, but in case others do not read it it would be good to point out if i am way off base here. i'd like us all to avoid premature death if at all possible.

Dan

Dan Fitzpatrick wrote: by the way, 2x6x10 are 5.40, and 2x8x10 are 7.27 at my home depot. in case that helps (not that you'd cut costs here, mind you ) ... there is no reason NOT to overkill here where life is at stake of course, especially for a few dollars. i just put that for the curious.

i might also add that 2x10x10s are 9.98 and 2x12x10s are 11.85 ... just in case you want to be REALLY safe!

I was aware of that - the 2x ? is the size of the member in the rough (Nominal Size) - after dressing it's generally 1.5 x ?.5 (rule of thumb - have seen as low as ?.25 and as high as ?.3/4

They (also) were aware of that - it's part of the reason for their insisting that engineers use that particular publication for design purposes. It takes into account Size Adjusted Design Values.

Still looking into things - busy as a one armed paper hanger here right now - we are trying to close this project out in the next 5 weeks - it's always a killer schedule at this point on any project.

Rod

From http://www.rugglumber.com/contractors/c ... size.shtml:

(Edited to exclude image of lumber size chart comparing nominal to actual, since it ends up that isn't what Dan was talking about! You can still follow the link above if you want to see it.)

sharward wrote:

Ballgame wrote:wow its a hornets nest in here.

You must have mistaken the buzzing sound for hornets, Ballgame -- that's my brain frying!

This looks like a ton of work man.

Actually, according to my abacus, it's probably more like 35 tons!

Good luck

Yeah, I'm going to need it! Of course, this isn't etched in stone yet... I'm just trying to wrap my head around the possibility of doing this.

Scary indeed!

Well you sure are doing your homework. But let me play devils advocate…is it worth it? Looks like you have a ton of work ahead of you and are going have to redo part of the house all for a space to play. My wife would kill me if I were doing this haha.

Ballgame wrote:But let me play devils advocate…is it worth it?

Making a 20 year dream come true? Yes.

Looks like you have a ton of work ahead of you and are going have to redo part of the house all for a space to play. My wife would kill me if I were doing this haha.

I'm very fortunate to have a very supportive wife. I'll bet if you had a 20 year dream, your wife would support you too.

I was aware of that - the 2x ? is the size of the member in the rough (Nominal Size) - after dressing it's generally 1.5 x ?.5 (rule of thumb - have seen as low as ?.25 and as high as ?.3/4

um ... huh?

those were supposed to be PRICES at home depot sorry, i did not put in the $ sign.

yes i WOULD think you were aware of the dimension thing, Rod ...

sorry to be unclear

dan

Thought that was what you were quoting, but wasn't sure - kind of a "co-inky-dink" on how close prices run to sizes

sharward wrote:

Ballgame wrote:But let me play devils advocate…is it worth it?

Making a 20 year dream come true? Yes.

Looks like you have a ton of work ahead of you and are going have to redo part of the house all for a space to play. My wife would kill me if I were doing this haha.

I'm very fortunate to have a very supportive wife. I'll bet if you had a 20 year dream, your wife would support you too.

shit if my wife can put up with me for 20 years SHE can do whatever she wants

So whats the next step for you here?
Since my basement floods here is my studio

knightfly wrote:Thought that was what you were quoting, but wasn't sure - kind of a "co-inky-dink" on how close prices run to sizes

yeah steve that is an odd coincidence.

but i still have to wonder what type of measuring device y'all pictured me using at home depot that measured 2x12 lumber to the hundredth of an inch ... maybe i brought my extra large dial caliper

i mean i AM a geek but REALLY

Nearly a year ago (July 2004), before we even moved into this house, I exchanged e-mail with Keith Yates, a world renowned home theater designer who just happens to call the Sacramento area his home. My first reply from him included a recommendation for Acoustics & Vibrations Group here in Sacramento. They don't have a Web site yet, but here's the founder's bio:

• Steve Pettyjohn is a registered Professional Engineer in Acoustics in Oregon. He receiveda Bachelor of Science degree in Mechanical Engineering from OSU and a Master of Science degree in an acoustics multi-disciplinary program in 1979 of the School of Mechanical Engineering from the Georgia Institute of Technology. The Vibration Institute certified him in 1994 as Vibration Specialist II.
  
  After completing twelve years of acoustic andvibration research for Cummins Engine Company and acoustic and vibration consulting for firms in Georgia, he formed The Acoustics & Vibration Group (TAVG) in Sacramento in 1986.
  
  He is a member of The Vibration Institute, The Acoustical Society of America (ASA), Institute of Noise Control Engineers (INCE), American Society of Mechanical Engineers (ASME), and American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE).

Them's a lot of letters!

In speaking with the Mason Industries representative whose territory includes Sacramento, Pettyjohn's firm came up again as a recommendation.

So, duh, I called them a couple of days ago, and I followed up with them today. I'll be meeting with their in-house studio guy (his name is Brian) next week to go over photographs and my wannabe drawings and discuss next steps.

At a billable rate of $124/hour (2 hour minimum), I'll need to talk fast!

I'll probably have to budget about $1,000 for some wall and ceiling specs and drawings, and (of course) some firm advice on whether or not I should float the room (and, if so, how).

I'll be very busy this weekend tidying up my illustrations and gathering my notes so as to make the most of my time with Brian next week!

I'm so glad I have acquired all of this knowledge leading up to this meeting. What a head-start I'll have!

I'll keep y'all posted (of course).