# Splicing loft floor joists



## WoodZenStudent (Mar 25, 2021)

I'm adding a 15'x15' loft over one side of my shop. I'm using 2×8x15 wood joists. However, the pieces are too long to put into place as a whole piece. I was thinking about cutting them down and splicing them back together once in place. Roof is already on so there is no way to do it the easy way.

Here's my plan:


Cut the wood into two pieces
Put the two pieces together in place and splice them using 1/2" plywood, glued and screwed (both sides)

Would it matter if all were cut in the center or should I stagger the cuts of each board? How long should the splice be? The span is 15'.

Any better ideas?

The loft will be used mainly for storage (scraps of lumber, holiday stuff, etc.). There is no crossbeam running down the center.


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## Ocelot (Mar 6, 2011)

Pictures would help a lot.


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## Ocelot (Mar 6, 2011)

You might consider a scarf joint.


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## WoodZenStudent (Mar 25, 2021)

Hopefully, you can see the pics. I plan to put it over the garage door.

https://1drv.ms/f/s!Ark3-0_Xv9Qdhq1_m57YpsfBAVKXmA


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## corelz125 (Sep 23, 2015)

Its empty in the pics. You can't get them at full length or can't get them to the shop at full length? Definitely stagger them if you do cut them.


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## WoodZenStudent (Mar 25, 2021)

I can get them in full lengths. Just just won't fit into the space needed as one solid piece.

The picture is loading upside down? It looks normal on my laptop.


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## CWWoodworking (Nov 28, 2017)

Put a ledger board underneath the ends and leave them whole. I would use bigger than 2×8

I would not cut them under any circumstance


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## CaptainKlutz (Apr 23, 2014)

+1 Would not cut them under any circumstance

Splice load bearing joists are supposed to be supported under the splice area per IRC. There are approved methods for repairing a damaged joist. These require addition of sister joist(s), adhesives, and fasteners. Need to consult a structural engineer or your local building inspector for methods approved locally. Splicing joist usually means putting up 3 boards instead of 1. With current lumber costs, would try hard to avoid splices.

+1 Double check size of lumber .vs. weight loading capacity. 
Typical 2×8 length limit used as load bearing floor joist 16" OC is ~10-12ft for SYP. SPF framing lumber is shorter. Might want to look at IRC (building code) chapter 5, Floor Joist spans table.

+1 Add a ledger board, 
and use face mount joist hanger's.

Have you tried to fit a 15ft board in that space yet? 
Appears the garage door and track are above the header plate on walls. 
hmm?
Where are you going to attach the loft joist, half way up the roof framing? Then can not use ledger plate and hangers. Plus, Will roof joist anchor point support the weight? Due you have hurricane, coastal wind, or snow loads to accomidate on roof/walls, that subtracts from possible loft weight loading?

Don't shoot the messenger. 
Am sure there a many *********************************** ways to slap loft floor up there that might work for awhile, 
until it comes crashing down on top of your vehicle or tools parked in garage. 

Be safe, not sorry.


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## therealSteveN (Oct 29, 2016)

Best case scenario is you must put the loft on the back half of the building. As Capn K pointed out your door is going to be in the way of doing anything up front.

Now you are saying you are building a 15×15 loft, then you say a 15" 2×8 won't fit? *So what is the actual measurement side to side on the top of your top plate?* Whatever that is is where you will set the joists. Actually all of this should have been done before you put the roof on, A lot easier, and probably to a better end.

I also am wondering where you got info that on a 15' span a 2×8 was sufficient to bear weight of a loft, much less put anything on the loft floor? You could use a 2×8 if you were working on 10" placement, but if this is to be looked at for code, you should be looking at 2×10. Back the width to 10 or even 12' you might be ok, at 15 2×8 is light. I am talking side to side width, the measurement I asked for.


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## MadMark (Jun 3, 2014)

Plywood won't work. Splice plates are usually 1/4 or better cold rolled steel 24" long and full width. Agree 15' unsupported is too long for 2×8's.

You should have saved the cost of the 16's and just bought 8's if you have to cut them.

What are you going to support this with? You can't splice a cantilever (well YOU can but I won't walk on it!)


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## tvrgeek (Nov 19, 2013)

Read the "Captain's" post carefully.

Now, you don't say what this loft is to be used for. Do you intend to use it as work space, as in walk in it? Or is it to be just ab open shelf you set a ladder against and store a few light items? Empty boxes, x-mas ornaments etc. The following is the assumption you want to use the space.

If you were in an agricultural zoned space and no building codes, I might double sister with a 10 foot 2×8, but I am sure that would net meet code. Remember code is MINIMUM. Anyone who does not like trampolines for floors goes one size larger.

I do not see how you think you are going to get a minimum 8 foot garage ceiling below a loft floor. That door does not look like an oversize 8 footer, so I am guessing, correct me if I am wrong, but your walls are only 7 foot.

Look at code for the stairs. There are minimum head-rooms. Stairs that meet code can take up a lot more space than you expect, especially when a sloped wall or ceiling is in the way.

Remember, all lumber is not the same. The junk sold at the local stores in not the same strength as what it used for pre-fab roof trusses. Again, the code will tell you max span for various options.

In other words, an open loft "shelf" makes sense for light storage in a garage. I do not think anything else would be wise in the building as I see in the picture.


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## tomsteve (Jan 23, 2015)

2 by 8 shouldnt span 15 feet. in the pics in the link it appears there are 2 in place already. those are collar ties. their purpose and load are different than floor joists. they are intended to keep the walls from bowing out so have no load on them on them.
rule of thumb i was taught quite some time ago:
2 by 6= 6' span
2 by 8= 8' span
2 by 10= 10' span
2 by 12=12' span

ive added loft space to a structure with a gambrel roof. we were able to get the floor joists in with full bearing on the walls. tricky but doable

itvrgeek brought up a good point about about quality/species of lumber used between framing and trusses. typically the bottom cord will be yellow pine. the top cord and webs are syp BUT that syp isnt the same as big box junk. it will have tighter growth rings.

if you were to use yellow pine, youd still want 2 by 10 for floor joists


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## higtron (Jan 26, 2011)

Nail or screw a ledger at the height of your loft joists, cut your joists to the length between the ledgers and use joist hangers (Simpson hangers) to attached to the ledgers just like you would build a deck.


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## Knockonit (Nov 5, 2017)

no header on overhead door, could be an issue, what is loft used for, perhaps divide in two, beam in middle, hang joists on beam side to side then joist short way, one can splice a beam if done correctly, or build a flitch beam to carry load. if spaning the 15 ft, diaghram block it, on joints of plywood, will help with load. 
good luck, give it a whole lotta thought of use and design 
rj in az


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## CWWoodworking (Nov 28, 2017)

You could run an LVL in the front and it would be a lot less bouncy and is only 30$ more than a 2×12.


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## Knockonit (Nov 5, 2017)

12'' lvl are running around 14.00 a foot


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## JCamp (Nov 22, 2016)

Could you use 1×8s, flex them into place then screw them together into a 2x? I don't know how that would effect structural integrity tho


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## CWWoodworking (Nov 28, 2017)

> 12 lvl are running around 14.00 a foot
> 
> - Knockonit


105$ at Menards. 1.75×11.25×16'


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## Knockonit (Nov 5, 2017)

12'' lvl are running around 14.00 a foot


> 12 lvl are running around 14.00 a foot
> 
> - Knockonit
> 
> ...


wowza, need a menards here in phoenix


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## Knockonit (Nov 5, 2017)

i just checked my invoice on the 11-7/8'' x 1.75 '' lvl, we paid 11.95 plus the governor fees. so shade over 13. a foot, and if you add delivery well , amazing in regard to pricing due to geography
rj


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## MadMark (Jun 3, 2014)

Don't forget the exchange rate $ CDN vs $ US …


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## CaptainKlutz (Apr 23, 2014)

*WoodZenStudent*
Went back to your previous post on new shop, and found more pictures. 
Looking at everything, that building was not designed/built to have a serious loft?

Don't have any dimensions, but the lack of headers over garage door and side door, makes it appear the top plate is only 8ft above concrete? Very hard to use conventional ledger plate/hanger method for 15 foot span, as you will loose nearly foot in ceiling height, ending up with 7ft ceiling under the loft. 

One solution might be to build a 'deck' loft, using support posts. Since deck post would be placed couple feet from walls to reach up into roof space, could use the space between posts for storage shelves/cabinets, and/or side closet(s) for things like DC/compressor. Would essentially be building a 12' wide room with 8ft ceiling, between the existing 16' wide space. Would make a nice finishing room, or pleasant hand tool workshop with some double doors on end?

IMHO - cost to build a smaller room inside the building could be high enough, might be cheaper to unscrew the metal roof panels on a loft portion of Gambrel roof, cut out portion of plywood panels, install proper sized joists on header plates (don't forget earthquake structural ties), then rebuild/repair roof? Sucks to tear apart new roof, but sometimes it is cheapest method, and wastes less space than other options.

BTW - Am not a contractor, carpenter, or home builder. Just an engineer with some experience on home remodeling, and a ton of industrial facility projects. Please consult a professional in your frigid Alaskan area for best advice to met local requirements.

Best Luck.


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## gdaveg (Aug 1, 2020)

Yes 2×8's are too small, CWWood, Capt.K and others are right. 2×12's are not overkill.

But everyone here has built a tree fort and hung their 80 pound body on a rope tied to a nail in the tree.


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## ibewjon (Oct 2, 2010)

Seeing no header over the door, and 24" centers on upper wall tells me a lot. Good luck when it all comes tumbling down. A good wind may just fold it over.


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## WoodZenStudent (Mar 25, 2021)

Thanks everyone! I greatly appreciate your feedback and enthusiasm. I can't wait until I can actually start working on wood projects.

To reiterate, I planned to use the loft area - above the garage door - for storage (Holiday/seasonal stuff, clothing, etc.). I don't plan on anything really heavy.

I did some research prior to posting and read lots of mixed recommendations. I knew that span was going to be challenging but found something that said it would be ok at 13' or 14' as long as it was not taking a heavy load. Again, I knew it would be a challenge. It does appear I need to reconsider the size and perhaps opt for 10" or 12" if I can do this at all.

Background: This shop was built prior to us buying the house. I would have done quite a few things differently but I'm trying to make the best of what I have (safely and within financial reason). Some of the things done, frankly, have my head shaking.

I thought about a ledger board, but with 7' walls, that would put the ceiling really close to my head and the top of my side-by-side so I'm not sure that is an option. I would end up with something like 6 foot or less ceiling clearance.

Yep. The garage door is above the top plate (hmmm, indeed) which is why I planned to raise the joists. But as someone pointed out, the gambrel trusses(?) might not be able to support that added weight.

I made a miscalculation. I bought 16' boards and did not cut them down. The opening to place the boards on the top plate is roughly 15'. So if I trim down the boards a bit, I should be able to get them to fit and sit on top of the top plate. That said, it really sounds like my 2×8 is too weak. I may just end up building a separate storage unit.

Again, thanks for all the input!


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## corelz125 (Sep 23, 2015)

Already bought them so you're stuck with them now


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## northwoodsman (Feb 22, 2008)

Do you have the roofing materials in place already? If not cut a little slot in the roof and slide them in. Put the piece back in and glue a small piece of OSB on the inside to keep it in place. There is no way you are going to be walking on that portion of the roof at that angle, it's almost vertical. As someone else mentioned why is there no header, or even an attempt at one, over the garage door?


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## CWWoodworking (Nov 28, 2017)

> Do you have the roofing materials in place already? If not cut a little slot in the roof and slide them in. Put the piece back in and glue a small piece of OSB on the inside to keep it in place. There is no way you are going to be walking on that portion of the roof at that angle, it s almost vertical. As someone else mentioned why is there no header, or even an attempt at one, over the garage door?
> 
> - northwoodsman


I believe this is one of those prebuilt shed type deals. They don't really do headers in them. While I would never use a lot of their building practices they are usually ok structurally because of the small size. The whole building is only 16' wide. My guess is that it's also sided with T11 siding, adding strength.


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## CWWoodworking (Nov 28, 2017)

If you can't take the 8s back, buy 2 lvl beams. One in the front, one in the middle and use the 8s in between.

While the lvl's add cost, it's better than buying all new


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## controlfreak (Jun 29, 2019)

Just because you won't put a lot of weight up there doesn't mean someone else won't come along and load it up with lumber or whatever. I think you need to follow code for supporting a load per square foot or at least get close enough to it so as to not be grossly negligent. Might not be a bad idea to post a "Max Load _" to get an idiot's attention before they start hoarding wood after you sell the place.


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## PCDub (Sep 24, 2017)

> Already bought them so you re stuck with them now
> 
> - corelz125


Heck no! He's got gold on his hands! Put 'em up for auction and watch the bids go up! 
;-)


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## tvrgeek (Nov 19, 2013)

I think a storage shed is a great idea. We used to use our house attic, but that was when we had 3 inches of insulation and could deck them. I still have a garage attic that would be suitable for storage if I put in a drop down stair, but I have the luxury of a full load bearing storage loft in my shop so the junk I should toss has a home. Code for storage, but not occupancy. Different codes.


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## northwoodsman (Feb 22, 2008)

CWWoodworking - I have a similar shed, it was a kit. While I didn't redesign the framing I did notch out the 2" x 4"'s over the door and put in a 2" x 6" on edge. It may not have done much, but it gave me more of a piece of mind. I know that it won't be sagging and binding the doors.


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## CWWoodworking (Nov 28, 2017)

> CWWoodworking - I have a similar shed, it was a kit. While I didn t redesign the framing I did notch out the 2" x 4" s over the door and put in a 2" x 6" on edge. It may not have done much, but it gave me more of a piece of mind. I know that it won t be sagging and binding the doors.
> 
> - northwoodsman


If I were building a kit, probably do the same. There cheap for a reason though. I have one that's metal. 2×4 walls. Studs 3ft on center. Went through straight line winds that ripped part of my neighbors roof off so I guess it's fine. The skin on them helps sturdy them up.

I would not opt for a separate storage shed just because you have the 8s.

One of the biggest advantages of a gambrel roof is the ability to add storage relatively easy. Take advantage of it.


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## hotbyte (Apr 3, 2010)

Brother-in-law has similar storage barn. His has a narrow U shaped loft that doesn't encroach on door. I can't recall for sure, but I think it has a column at each inner corner of the loft.


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## corelz125 (Sep 23, 2015)

Auction off the lumber and use steel. Then you can put them in place and weld them back together.


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## therealSteveN (Oct 29, 2016)

> Already bought them so you re stuck with them now
> 
> - corelz125


YeahBUTT if he bought them 2 months ago, he could resell them, and almost build another shack, provided he can find cheaper wood down the road a bit.


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## bigblockyeti (Sep 9, 2013)

> Don t forget the exchange rate $ CDN vs $ US …
> 
> - Madmark2


Pretty sure AZ and IN are both in the go ole US of A?

Another vote for dont cut them. Was it mentioned was the OC dimension is? It appears the gambrel trusses are 24" OC, that will absolutely not work. My shed is a touch over 16' wide leaving a free span of 15'7" and I used 2×8x16' for the ceiling joists at 16" OC but it literally can't be over loaded with no ladder access other than climbing around the edge of the floor and between the joists. If planning on loading it up, you've been given several good ideas to make it more secure, yes, it's going to cost more $$ but not as much as having it fail damaging property and potentially hurting someone.


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## Sark (May 31, 2017)

Here's a idea, not yet discussed…and that is tying into the roof structure to help support the load. My mini-loft (more like a mezzanine) does span across the 20' garage with 2×4 lumber. 2×4 ties every 4 feet drop down from the ceiling joists. That means that the 2×4 is only supporting a span of 4' which is very strong.

This suggestion moves some of the vertical load from directly off the walls to the ceiling structure. Given the shape of your roof, that vertical load would tend to push or bow out the sides of the roof. Therefore you would need put in cross ties wherever you connected the loft to the ceiling.

In a way, this idea means creating a truss-like structure to help support the load. You give up having a completely unobstructed deck structure, but you gain in strength. My home has 26' free-span trusses that are 2' on center (so there are no interior bearing walls), and the trusses are all made of 2×4 lumber with the longest length of any of the lumber being 8'.

Not mentioned is the problem of seismic safety, and Alaska is known for earthquakes. If I were taking on this project, I would use the opportunity to install lateral bracing on the walls. Based on what I can see, this garage would flatten like a pancake in even a small earthquake.


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