Hi Larry, Some over kill, some under engineering.
Someone already mentioned 24 inch centers to be too distant. 2 by 6 is also way too light for joists and since you plan to use hangers, there is no good reason why the joists can't or shouldn't be at least 8 inches as is the rim joist. 2 by 8 inch joists though should be no further apart than 12 inch centers according to many building codes, 2 by 10 for 16 inch centers. Since your loft is 8 by 24 feet and you plan your outer rim to be supported on posts then you want your joists to run from that outer rim joist toward the wall. You shouldn't need that many support posts. One in the center leaves only two 12 foot spans which should be plenty. this also reduces the obstructions and cost. You can build up your strength across the spans by laminating three or four 2 bys rather than so many vertical posts. You might like to consider an engineered 'I' beam to span that distance. I am pretty sure you could have one sufficient to span the distance without any support. These are sort of truss designed beams, very rigid and so long as you have it well tied to the wall through the ledger board so that the beam cannot twist, it will not sag. Though more expensive, you won't have any support posts to be smacking into or getting in the way of swinging a long board around and you are saving the cost of those posts as well. 3/4 plywood is perfectly adequate for the deck on 16 inch centers, you can go safely to 5/8ths. Decking plywood is tongue & grooved rough old stuff and you can even get it in MDF but I don't recommend it, any moisture or even dropping a hammer from height can cause it to fail. Someone already mentioned bolting a single ledger board to the block wall and this is sufficient and as mentioned, nail a second one over the first. The loading is vertical so you would have to sheer the bolts and nails off for this to fail. You could of course use engineered joists for the entire structure which would make it very rigid but it would cost a bit more. How much height do you have above the floor? I suppose the converse is how much height will you have above your loft deck? You may be able to suspend the loft from the roof trusses depending on their structure. Dale Leavens, Cochrane Ontario Canada [EMAIL PROTECTED] Skype DaleLeavens Come and meet Aurora, Nakita and Nanook at our polar bear habitat. ----- Original Message ----- From: Larry Stansifer To: blindhandyman@yahoogroups.com Sent: Monday, July 30, 2007 2:06 PM Subject: [BlindHandyMan] Loft Hi Guys, Well you all have almost inspired me enough to attempt an 8x24 storage loft over one end of my shop. I am thinking 4x8 boards 24 feet long bolted through the outside block wall and another 24 foot long 4x8 bolted to 4" diameter support poles. The bottom of the floor would be 8 feet off of the shop floor. My plan is to cut through the concrete floor dig down about 4 feet and cement in the support poles. with the poles at 6foot intervals. I would install joist hangers every 2feet giving me 24" centers, using 2x6 joists to support 3/4 plywood flooring. Does this basic layout sound feasible? Do I need to double up the joists in the middle? What if any special tools will I need? I own a couple of cordless and air powered drills, wrenches, a saws-all and a second hand circ saw that isn't worth much.I also have a chop saw that I can put a wood blade in if needs be. I have read a lot of comments regarding the talking tape measure both good and bad. Do I need one or is their an alternative? Let me know what you guys think. I do have a friend who is a structural engineer and he told me he would be happy to look it over before I spend any money. Regards Larry Stansifer Thou art rewarded for thy results not for thine efforts. The Rogue Warrior [Non-text portions of this message have been removed] [Non-text portions of this message have been removed]
