[snrusnak]

Hi, I just signed up and am trying to gather some information.

I have a shop/warehouse that I want to build a loft/second floor in. This will be used purely as storage, and not for substantially heavy items(think boxes of xmas decorations, etc). The shop is 30' deep x 15' wide, approximately. I want to build a loft across the back of the shop coming forward 8'. This will give me an 8'x15' storage area off the ground. The ceiling is approximately 10' off the slab. I'll be putting the loft approximately 7' off the ground, giving about 3' of height for the loft, with plenty(depending on what size ledgers are used) of walking room below.

I am trying to reuse a bunch of materials that we brought from our last place which was much smaller. If it won't work, no problem, but if I can make it work it'll save me a little money. I have a bunch of 2x6's and 2x4's. Here's a couple pictures, The first is what I'd like to do(but I'm not sure if the 2x4's are strong enough). The second is another possibility.

Any help, advice, etc is greatly appreciated. Please keep in mind I don't need to meet any standards or codes, it doesn't have to be the most rigid floor in the world, I just don't want it to sag 6" in a year.

 

[woodnthings]

The 15 ft span is too long for your lumber ...

http://sterryconsulting.com/downloads/JoistSizeSchedule.pdf

This chart will specify the maximum span for each size of lumber for example a 2 X 6 will span about 10 ft with a 40 lbs per sq ft load.
The greater the load per sq ft, the greater the vertical dimension of the joist needed and/or the less span.

To span 15ft with a 40 lb per sq ft load, you will need a 2 x 10 on 16" centers. Best you consult with a licensed builder before building the loft. :yes:

 

[snrusnak]

Thanks for the feedback.

I completely understand about getting the right info but this is something that just needs to "stay up". lol. Think of it more like shelving, just bigger. I will use that info you provided.

At the last place we used 2x4's to span 8' but the ledgers were only spanning 8' as well. I know it wasn't proper but it worked fine. This is just a storage loft in a storage unit/shop/warehouse, or whatever you want to call it. I'm just unsure about going 15', not sure what I need. It sounds like I need a 2x10.

I'm thinking my 2nd attachment will work, but probably need to go with a taller ledger than 6".

 

[cabinetman]

We have an introduction section where you can say a few words about yourself. If you fill out your profile in your "User Control Panel", you can list any hobbies, experience or other facts. You can also list your general geographical location which would be a help in answering some questions.

While many of us will do structures in our "private spaces", advising you what will work, or not isn't based on any hard data. Just quoting some details from some chart doesn't take into account what the materials actually are, or what you have to install to. It's just a general guideline. Your plans may have a workable combination, but we aren't structural engineers. You might benefit from a "consultation" on site with one, so, the existing structure and proposed construction can be evaluated.

.

 

[MNsawyergp]

The 2 x 4's are pretty much worthless for an 8' span. The front beam would need at least one post, and would be better with 2. That beam should also be 2 or 3 pieces glued and nailed together. If you used your second drawing, where you are running 2 x 6's perpendicular to the front beam, double the front beam and those 2. Where you have 2 x 4 joists joining into them...instead, divide those three sections in half with another 2 x 6 beam 4' out from the back wall. Then, use 2 x 4's that will be 4' long to fill those areas. I still recommend at least one post on that front beam.

 

[snrusnak]

Thanks for the advice. What do you think about using my second option(5' span for the 2x4's) and using 2x8's for the ledgers? I can also add a post on the front beam 2' off the wall, cutting the overall free span down to ~13'. I can't do any more than than as I need it open underneath.

 

[cabinetman]

Thanks for the advice. What do you think about using my second option(5' span for the 2x4's) and using 2x8's for the ledgers? I can also add a post on the front beam 2' off the wall, cutting the overall free span down to ~13'. I can't do any more than than as I need it open underneath.

I wouldn't do any structural work like you are asking about using the suggestions from forum members. While those offering their opinions is a nice gesture, they aren't structural engineers, and bear no responsibility. They have no idea what the conditions are at your site, or the wood you have to work with.

What you do in your space may not follow code for your locale, and could affect or invalidate insurance coverage, or worse yet, become a health hazard.

.

 

[snrusnak]

I completely understand that cabinetman.

Please understand, and I don't mean this to be rude, but I'm not going to spend hundreds of dollars on a consultation with a structural engineer for a $200 loft that I'm building in a storage unit that is only occupied to work on my old truck 1 day a month. It's not in my house, or garage, or anything like that.

Obviouosly I don't want it falling down. I'm not a guy that doesn't have a clue, I work for a commercial masonry contractor and have an engineering degree(not structural), I am just trying to get a little input from guys that know more about wood trusses/joists/etc. I know that it's not technically going to be correct, I just want it to stay up and be good enough for my use.

If I were building an addition on my house or something like that I'd pull a permit, have an engineer design it, have it inspected, etc. Building shelves in the garage, not going to do that. A storage loft in my storage unit, not going to do that.

I hope you understand I'm not trying to be rude just trying to get the scenario across this is not something that is in need of being designed/consulted by an engineer.

I know 2x4's aren't the wisest choice, but I used them at my last place to span 8' and it worked. I'm fine with using them again to span 5' like my "option 2". My only question now is can I span 13' with a 2x6, 2x8, or 2x10 for a ledger(I believe this is the correct term)? I know it's not allowed for a floor joist by code, but in your opinions(as this is your field), is it good enough for my application?

That's all I'm looking for is some input.

 

[woodnthings]

here's what I'd do

Divide your space 15 x 8 ft into 2 areas across the width, right to left. They would measure 7.5 ft X 4 ft. Use a double 2 X 8 or 10 across the width (15 ft) at the front and across the center at 4 ft in. Then your 2 x 4's will span only 4 ft in between the two "beams".

Or you can divide the space into 2 areas each measuring 7.5 ft X 8 ft. Run a center double or triple 2X 10 support beam with a post at the front edge or in a few feet. Then your 2 X 4's will span 7.5 ft right to left.

As an engineer you know about supporting loads with posts and hanging the floor "joists" from ledgers. What you are trying to do is minimize the span, allowing smaller "joists", and distribute the loads to the beam and outside walls.

As far as anyone taking responsibility for any information posted here the "Warnings" at the beginnings of each thread should suffice.
Should anyone choose to start a lawsuit about info posted on a forum and injuries result in the "application" of that information, good luck. You asked for advice "informally" and that's what I am giving you. No contracts, no responsibility, no lawsuits, no BS, just free "advice" nothing more... :yes:

Just imagine the juries reaction or the judges, "I saw/read it on the internet" ..."Case dismissed."

 

[snrusnak]

I completely understand all of your comments/concerns. Believe me I'm not going to start a lawsuit LOL. It's a shame now a days that that's the first thing people think about, although I completely understand your need to protect yourself in our current society. Just one of the many things wrong today...but I digress...

I'm completely on board with what you're proposing, thanks.

If I found it to be worth while to purchase all new 2x6's, I think I'd be ok making the 8' span with 2x6's, yes? If I did that, would a 2x10 ledger suffice for the 13' span? I can sister a couple 2x8's or 2x10's for a ledger if need be. I'm just looking at all the cutting and fitting of the 2x4's, it will take a lot longer. Maybe I will just give in to the 2x6's and use the 2x4's for shelves or something else. And then you all don't have to pull out your attorneys' phone numbers :shifty:

 

[cabinetman]

I completely understand all of your comments/concerns. Believe me I'm not going to start a lawsuit LOL. It's a shame now a days that that's the first thing people think about, although I completely understand your need to protect yourself in our current society. Just one of the many things wrong today...but I digress...

It's a safety issue, not a lawsuit issue. You'll find information on the internet on some subjects that's pure opinion, whether it has any substance or not. You'll also find that many answers won't even be close in agreement. Some need to respond just to push the issue of playing engineer.

If you are interested in internet responses, try a structural engineering forum, or maybe a carpenters forum, where some members do this kind of work professionally on a daily basis.

.

 

[snrusnak]

Ok, I may need to look elsewhere for more info. I do appreciate the input given.

I think I will go with the 2x6's to be safe and save some work. Based on the table in the link in the second post, spanning 8' with 2x6 joists at 24"oc should be no problem.

Really my only issue now is the sizing of the front beam ledger.

 

[woodnthings]

Do you have a framing carpenter friend?

If so, that's who I would consult. I have done a considerable amount of framing and construction, but I am not a "framer", just have some first hand experience:

 

[snrusnak]

Wow, I feel dumb now My father in law has a lot of experience with framing(does millwork now), and one of our superintendents that I know fairly well was a framer most of his career. Can't believe I didn't think to ask them. Thanks.

 

[FrankC]

Have you considered a U shaped shelf possibly suspended from the ceiling, 8' seems rather deep for most storage unless it is for lumber which would be another whole story.

 

[snrusnak]

The problem with suspending it is the ceiling is drywalled, and the roof is steel joists. If it was open wood trusses I'd be all for that, but it would be a lot more work with the unit we have. I have no idea what the drywall ceiling is attached to(if they framed it down with wood, or what). The ceiling was added by the last tenant, as they used it for an office.

The thought of tearing down the ceiling crossed my mind, but after finding out there's only about 1' of space to gain to the deck/roof above, it didn't seem worth it. There are also a bunch of lights installed on the ceiling which I'd have to move, etc, and reroute. Just seems like a PITA.

The plan is to build this loft on saturday, and be done at the end of the day.

I know and agree 8' deep x what will be about 2-3 feet tall is a deep and shallow storage area but our goal is to get things up off the ground so we have room to work on the truck.

I guess the intent is to have something like a "mother's attic" in a uhaul truck, but much deeper. We are only going 8' deep because that's what 2 by's and plywood comes as. We could go 4' deep but I'd rather have some more room.

We will also build a 2' deep x 8' wide workbench underneath on one side. That's where the 3rd 4x4 support post comes in to play, bringing the clear span down to about 13'.

 

[cabinetman]

Wow, I feel dumb now My father in law has a lot of experience with framing(does millwork now), and one of our superintendents that I know fairly well was a framer most of his career. Can't believe I didn't think to ask them. Thanks.

There ya go. :yes:

.

 

[snrusnak]

Got it all sorted

I called the superintendent that I know through work and he believes 2x6 joists at 2' oc with a single 2x8 ledger(with a 2x4 ledger attached on he inside for the joists to bear on) will be sufficient for my use.

Thanks for the help. I can post finished pics after it's done if you all are at all interested?

 

[woodnthings]

framing terms

Ok, see if this will help for now and in the future.
studs and joists and rafters and beams and posts and ledgers all defined here:
http://budget.net/~brich/terms.html

For example a ledger is a board attached to either a wall or a joist that other framing members rest upon, including smaller joists.
Joists run horizontally, rafters are part of the roof and run at an angle, posts are vertical and support beams. etc .....

 

[snrusnak]

Well, we've changed plans a little and this loft is becoming more of a shelf. We decided we didn't want to lose as much head room, so we are cutting the depth in half. It will now be 15' x 4'. This will also allow us to reuse the 2x4's for the joists (only spanning 4' now) and not buy 2x6's. We will still be using 2x8's for the ledgers.