Engineer's Advice needed-home pool room

K

KMRUNOUT

AzB Silver Member
Silver Member
Any engineers out there?

I am planning on building a pool room in my attic. I have lots of space. The only potential problem is that the floor joists are 2x6, spaced 24" on center apart. The span that these joists cover is about 14'. I will start out with an 8' Brunswick with 1" backed slate, all wood-which I already own. This table probably weighs about 800 lbs. I want to eventually put in a GC IV.

What do you think? Will I be ok with a 3/4" plywood floor, or do I need to think about doubling up studs or something?

I've had people tell me "sure-you could put a car up here-there's no problem with the structure-just get a solid floor". Also, I've heard no chance without beefing up the floor. Any input would be welcome and appreciated.

Thanks,

Kerry
 
KMRUNOUT said:
Any engineers out there?

I am planning on building a pool room in my attic. I have lots of space. The only potential problem is that the floor joists are 2x6, spaced 24" on center apart. The span that these joists cover is about 14'. I will start out with an 8' Brunswick with 1" backed slate, all wood-which I already own. This table probably weighs about 800 lbs. I want to eventually put in a GC IV.

What do you think? Will I be ok with a 3/4" plywood floor, or do I need to think about doubling up studs or something?

I've had people tell me "sure-you could put a car up here-there's no problem with the structure-just get a solid floor". Also, I've heard no chance without beefing up the floor. Any input would be welcome and appreciated.

Thanks,

Kerry
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The best advice I could give you is don't get advice here. You really need a specialist to look at your attic floor. I have friends who are engineers and have taken a few courses in what you want done and know enough to say, you don't want Bobby The Weekend Handyman telling you what to do.
 
no way

I'm not a builder, however even if the 2x6 boards hold the weight i'm sure the 3/4 plywood would move (dip) over time with that much weight on it. I would for sure improve the flooring.
 
The short answer is No. Based on your description you are a long way from making that a usable space, much less putting an 8' slate table up there. You need something along the lines of 2x10's or 2x12's on 16 inch centers for that span.

Btw, I have an ME degree and also remodel attics and basements for fun and profit.
 
I'm with Endymion. 2x6's seem pretty small!

A lot of it depends on the quality of the joists. Are they cracked, checked, etc.. What is the connection at the ends? Are they just toe nailed or do they have brackets with nails? How many nails? I'm assuming the 2x6's are on edge and not laying flat? You can distribute out the load of each leg using square pads too. Are you able to center the table in the room so that the legs are directly over a joist or floor beam?

Oh, I'm a registered Professional Engineer that design bridges for a living. ;)
 
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Jude Rosenstock said:
The best advice I could give you is don't get advice here. You really need a specialist to look at your attic floor. I have friends who are engineers and have taken a few courses in what you want done and know enough to say, you don't want Bobby The Weekend Handyman telling you what to do.
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I completely agree. This is a fairly simple question for a structual engineer, I think.

As a first-glance test, try this: get 4-5 adults to stand (or sit on a sofa) in the space where you will put the table. Listen to and watch the floor while they get into place. If the floor moves or groans you may have a problem. Regardless of the result of this crude experiment, get an engineer before you hump that slate up the stairs.
 
As a Architect

KMRUNOUT said:
Any engineers out there?

I am planning on building a pool room in my attic. I have lots of space. The only potential problem is that the floor joists are 2x6, spaced 24" on center apart. The span that these joists cover is about 14'. I will start out with an 8' Brunswick with 1" backed slate, all wood-which I already own. This table probably weighs about 800 lbs. I want to eventually put in a GC IV.

What do you think? Will I be ok with a 3/4" plywood floor, or do I need to think about doubling up studs or something?

I've had people tell me "sure-you could put a car up here-there's no problem with the structure-just get a solid floor". Also, I've heard no chance without beefing up the floor. Any input would be welcome and appreciated.

Thanks,

Kerry
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:) My advise is to have a licensed and certified builder or architect look at your structure in order to evaluate it ! there is no way I or anyone else can or should advise you without seeing the intended area! for several reasons ! you would need to know the age and condition of the 2x6's the general structural integrity etcetera Please do not allow someone to advise you without these prerequisites ! ;)
 
MrLucky said:
:) My advise is to have a licensed and certified builder or architect look at your structure in order to evaluate it !
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Please listen to this advise. It may seem like an unecessary expense right now, but how would those costs compare (in hindsight) to the costs of repairing structural damage to your home? This is not something to take lightly.

BTW, not that it matters...but I hold degrees in several disciplines of Engineering (including a Masters, MSEE).
 
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longhair said:
As a first-glance test, try this: get 4-5 adults to stand (or sit on a sofa) in the space where you will put the table. Listen to and watch the floor while they get into place. If the floor moves or groans you may have a problem. Regardless of the result of this crude experiment, get an engineer before you hump that slate up the stairs.
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Also, if the floor caves in and your friends/family plummet through to their deaths/maimings, then rethinking the idea of putting a table up there is in order. :P

I agree with some of the other folks - get a real live engineer to come eyeball your attic.
 
Please don't try the experiment someone suggested where 5 or 6 people walk around your attic to see what happens. The 2x6's are sufficient for handling the dead load of rock/plaster/flooring plus the random storage and an additional live load of a couple people climbing around. You will most likely crack your drywall or your plaster if you get a lot of bodies up there.

An experiment that you can try involves only two people. You stand still in the center of the space while a decent size friend walks around. While it is very difficult to sense bounce in span of floor by yourself', it's very easy to tell w/2 people.

Most importantly, don't listen to any of those EE types! ;-)
 
MrLucky said:
:) My advise is to have a licensed and certified builder or architect look at your structure in order to evaluate it ! ;)
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You don't need no stinkin contractor. Should be just fine. Use lots of good strong duct tape. ........ J/K:p

Get pro advice as mentioned. Studs spaced at 24 inches under 3/4" plywood sounds bouncey and prone to sag to me. Good luck w/the new room!
 
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KMRUNOUT said:
I've had people tell me "sure-you could put a car up here-there's no problem with the structure-just get a solid floor".
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Based on the existing conditions you have described, whoever told you this deserves a serious beating.

As a contractor, the advice to get a professionally licensed structural engineer, one with solid experience in residential construction and remodeling, to get out and take a look at your situation is your only option.

The thickness of the floor or subfloor has nothing to do with the structural integrity, or support strength of the floor. In fact, by "just getting a solid floor" you are only adding weight and making things worse.

Around here, a formal structural analysis like this accompanied by a letter stamped with the engineer's seal would cost anywhere between $500 - $1000. Any drawings would be extra. If he or she comes out and some of the things they tell you definitely kill the possibility of going forward, you can probably just pay them one or two hundred bucks for their time and call it a day.

Good luck! :D
 
I say tie some chains around those 2x6s, then bolt em to the roof rafters and you will have yourself a mini Golden Gate bridge that you can drive across. :) no .. no I'm just kidding.


Our first home (a rent) 30 some years ago was in an older 2 family house. We had the second floor and attic. It was an older home and it was 2x8 16 oc. I put an old House Of Lords 4.5 x 9 table up in the attic.

It was murder getting the slates up there and I had 4 friends helping. When it was all up there we actually felt the attic kind of sway and there were a ton of interior walls below the attic. DON'T Mess around with this, you really do have to spend the bucks and get it checked.
 
Finding Joist Requirements

If I had your delema I would borrow or purchase a good book on outdoor deck building. In it you will find charts and/or graphs for loads, joist sizes, beam spacings, etc. Deck construction is designed for heavy loads. People congregating at a party on a deck could easily exceed 800Lbs or more in the area a pool table may occupy. I would use the deck book specs only if BOTH ENDS OF YOUR JOISTS ARE RESTING ON A PLATE (A 2X) AND NOT HANGING FROM A WALL STUD. I also believe a good quality sub floor material well fastened WILL in fact greatly enhance the overall strength and stability of the floor. If possible, place the table legs or feet on top of "cats" between two joists. This will aid in two joists carrying the initial load on each end. Hope this helps!

I have no degree in anything, just expeience and common sense
 
Thanks everyone for the responses. I think the concensus opinion is what I thought in the first place, which is that I should probably have someone strengthen up the floor.

I didn't mention that the house was built in 1890. The joists are definitely sitting in the common on-end configuration (not laying flat). They appear to be in decent condition, however they are old, probably pine. I guess I will start shopping for a contractor.

Thanks for the advice guys.

Kerry
 
If you get a chance look at my table and light in the main forum a couple pages back called Diamond table under light and see if my space looks like what you have, I have 16 ft 2x12's doubled at every joist crossing the 22 ft length and boxed the spots between the joist where the legs of the Diamond 9 footer would sit just to keep everything level and I am also lucky that the table straddles the load bearing wall from lower level or 1st floor. My carpenter suggested this overkill while building the upstairs floor since all he was hearing was me kicking his but playing pool for his bill when I got the table ready. You will also have several people standing on the floors at times around the table if you have company so build it strong the first time, it will suck to walk downstairs and see the ceiling bowing down even slightly and changing the level of the table. Good luck Leonard
 
try this deflection calculator

there is a floor joist deflection calculator on the Tile Your World website. It checks to see if the floor joists are rigid enough to tile over, I'm guessing that you would want a pool table to have similar properties. Bottom line, the 6" joists on 24" centers & 14' span, fails miserably. Check it yourself if you want to try some other options.

http://www.johnbridge.com/vbulletin/deflecto.pl
 
The best advice I could give you is don't get advice here. You really need a specialist to look at your attic floor. I have friends who are engineers and have taken a few courses in what you want done and know enough to say, you don't want Bobby The Weekend Handyman telling you what to do.
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This is the best advice I've heard all day.
 
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