Rafter Ties Versus Ceiling Joists - Which One Do I Need?

www.homebuildingandrepairs.com... Click on this link for more information about roof framing, garage building and home remodeling. This video should provide you with enough information to tell the difference between a ceiling joist and a roof rafter tie. Rafter ties are used to create a stronger connection between the roof rafters and the wall framing plates, while ceiling joist are used to support wall plaster, drywall or other materials used to create a solid surface ceiling.

[@gamervisions9947]

Could u possibly make quick videos describing what is a joist? Or what is blocking, backing, or header joists. I'm still learning framing and you using an animation of the frame work is really beneficial to see what the components are and their job. I'm currently in college and still new to alot of this thank!!

[@nairbudy6403]

Love it when these vidoes show up... Im not even building but very interesting stuff!

[@UncaDave]

Love the computer animation for describing what the possibilities are. Good show!

[@gregvancom]

Thank you very much!

[@atgradio252]

good day. am interested in strengthening the roofing area to use space, which needs to be accessed for general electrical and plumbing, but additional to add a bit more storage space and provide ability to walk up. currently, whatever is there is swaying/moving considerably. my initial thought was to block it off with cut 2x4s but not so sure any more. what would cause the considerable movement that i have now? this area is overa 1/3 of the garage area that then butts up to 2nd floor master bath overhead.

[@allendiaz662]

This is just what a was looking for Thanks!!!

[@gregvancom]

You're welcome and I'm glad it helped.

[@user-bk7kc5yn2n]

I have seen many of your videos in which the ceiling joists/rafter ties are laid on load bearing walls. My garage is different as its 2x6 ties are laid on the 4x14 garage header 48".0 OC on one side. I want to reinforce it by adding 2x6 joists 16" OC so that I can install ceiling. Noting that 2x6 Douglas Fir #2 lumbers (21' long) are very heavy. Would you add more ties/joists? if I use rafter ties and braces in the middle of all joists. will that distribute the weight of the new joists on the other two sides of the garage? The current roof has rafter ties and braces 48" OC.

[@jakedillard9988]

Thanks for the info!

[@gregvancom]

Any time!

[@c.f.b9093]

The attic above the garage door is starting to lean forward and I'm afraid it starting to collapse due to the repeated opening and closing of the garage door...the wood frame for the door is cracking and above that the front and top of the roof is leaning forward...the heavy piece of wood that the garage door spring is attracted to is also cracking and the rafter ends are cracking...I have the same type of roof shown on the first part of the animation...in anyone can help me I'd really appreciate it

[@jeffreyroush595]

hi greg, i have a 24x24 attached garage with a ridge beam. it has 2x6 roof rafters 16 inch on center and 2x10 ceiling joists also 16 inch on center, room has 8 foot high ceiling and is drywall . i would like to raise a 12x12 foot section 2 feet in the center of the room (for a total of 10 feet height) would this be doable? i see that i need roof rafter ties every 4 feet but what about supporting the ceiling joists where i cut them. i am drywalling this cutout. thanks in advance

[@rotaxrider]

What if your garage is 21 feet wide what would you use for a ceiling joist?

[@babbetteduboise4284]

I'm hiring a carpenter to fix the poor construction from 79 in an addition. This helped hep me visualize what the roof inspector meant in the report.

[@ericfraser7543]

In order to get a greater span / usable attic storage, can you use engineered I joists to replace a traditional dimensional lumber for a ceiling joist? I would like to use traditional framing methods with a ridge board and collar ties, rather than a structural ridge beam. In that construction the I Joist ceiling joists are nailed to the roof rafters.

[@gregvancom]

I cannot provide you with engineering information, but can tell you that I've seen I joist used for floors in remodeling projects like you're suggesting.

[@ArtisanTony]

If you are going to remove rafter ties and replace them with ceiling joists you will want to install as many ceiling joists as possible first otherwise your walls will start to lean out depending on the spans and pitch of the roof it can be bad :)

[@gnarnal]

Hi Greg. Thanks for this great video. For a roof assembly with ceiling joists, can repairs be done to the load bearing by building temporarily wall under the ceiling joists, a few feet back from where the joists meet the rafters?

[@gregvancom]

That should work, but since I don't know exactly what you're dealing with, I would suggest going to our website where I have already created a few videos that might be helpful. www.homebuildingandrepairs.com/repairs/framing/index.html

[@matthewbrigham5981]

Love these videos..very thorough! I am building a simple 21x14' garage. My 2x8 joists will be 16oc. My plans don't include an attic access (stairs). I was wondering if you could cover how to frame an attic access the right way.

[@gregvancom]

I'm assuming this is going to be for a pull down set of stairs and if so, how big of an opening do you need and will the opening be parallel to the 14 foot or 21 foot side of the garage.

[@matthewbrigham5981]

@@gregvancom Yes that's correct. Rough opening 22.5 x 54". The opening will be parallel to the joists so on the 14' side.

[@gregvancom]

@@matthewbrigham5981 Obviously you will need to follow the installation instructions, but I think you would be safe installing double joist on each side of the opening with a double 22.5 inch blocks at each end, forming the desired rectangle. Let me know if this makes sense.

[@matthewbrigham5981]

gregvancom that’s very helpful...thank you. I’ll get a couple more joists and get moving. Thank you sir

[@gregvancom]

@@matthewbrigham5981 You're welcome and good luck on your project.

[@dustinb6906]

Your vid,s are always interesting. How do you propose getting those into place with an existing roof?

[@gregvancom]

For rafter ties, you can usually use smaller lumber and then lap them in the center and then secure together.

[@ram12e6]

How far can a 2×4 span and a 2×6 or where can I look it up for celing joist...thanks for the video

[@gregvancom]

The keywords you can type into a search engine might be something like," lumber span charts"or lumber span lengths. You can also get some of this information from the international building code books.

[@mattsgarageshop]

I think you answered this, but to be clear, if you’re using ceiling joists, you don’t need rafter ties - the joists serve a dual purpose in this case. You’d still want collar ties in the upper 1/3.

[@mikez9898]

I am going to build a 16x24 garage in the spring 2023. I wonder if I can use Simpson Strong-Tie 20-Gauge Galvanized Steel 1.25 inch wide Wood Straps, from top plate to top plate (the span is 16 feet) as a rafter ties. The rafters made out of 2x6x10 and are tied on top with 2x6 lumber.

[@gregvancom]

I don't know, but you can always check with the manufacture.

[@mattmcwhirter3603]

Hey Greg, I've got a 20'W x 22'L garage with a hip roof and rafter ties ever 48". I would like to add rafter ties (w/ blocking) to the last two rafters at the back of the garage so I can potentially create a loft for storage. My plan is to use blocking between ties and to tie into the top plate/rafters coming up on the backside of the garage. I would also have a vertical support in the center of each additional tie that connects to the king common. Do you see anything wrong with this or have any words of caution?

[@gregvancom]

I think I know what you're going to do, but am not 100% sure so I will leave you with this. Build what you're going to build and keep an eye on it. In other words inspect it regularly after you've completed the project to make sure it isn't falling apart for sagging. Keep in mind I cannot provide you any type of engineering information, because it could be confusing to other viewers.

[@sarahdouglass1353]

Thanks for the video! Would you mind helping with a related question? What if you are building a loft with the to of the floor 60cm below where your lowest rafter ties would normally go? Could those lower floor joists do a similar job as the rafter ties? It's for a 2m wide structure. Any insight would be greatly appreciated!

[@gregvancom]

Floor and ceiling joists can replace rafter ties, but I won't be able to provide you with any more information than that, because I cannot provide viewers with engineering information.

[@sarahdouglass1353]

@@gregvancom Of course, thanks. Your videos have been super helpful.

[@danpark417]

Hey Greg, great video! Question: I'm sheathing the roof with 4x8 cdx plywood on a flat roof, could I block between my trusses so that I can nail all around my plywood and have a more sturdy deck? I was thinking of using the H clips but I figure blocking would be stronger. Your thoughts?

[@gregvancom]

Yes, the blocks will make it stronger and the H clips work well also. I'm assuming that you have 24 inch on center roof rafter or truss spacing and if that's the case you might consider using thicker roof sheathing. Instead of using half-inch, you could try using 5/8. Tongue and groove plywood could also provide you with another option.

[@danpark417]

@@gregvancom You read my mind exactly! I tried 1/2in cdx but it still felt flimsy so I then tried 5/8 cdx 5 ply, and it's really strong. The rafters are 24in on center so I figure the blocking will really make for a strong roof deck before I use my torchdown rolls. Have a great day!

[@nickjoanshd5935]

Your the man

[@gregvancom]

Oh Yeah!!!!

[@redsresearch]

should be no problem putting a ceiling on 2x4 or 2x6, also what happened to the 50 nails

[@1weirddoe571]

How bad is it to sister 2 shorter Joists near the center so that you don't have to pay do much for a long span board. And/or brace that doubled up part to rafters or ridge?

[@gregvancom]

That is actually a common repair, but I'm not sure it's the best one, because it seems to add more weight to the structure. However, it is one that I've seen used by engineers.

[@jeffro1245]

so the area between the Rafters and floor joist are blocked or can you run a rim joist along the entire double top plate. also the blocking is that what sometimes is referred to as bird blocking?

[@gregvancom]

I would need to see a picture what you're talking about or provide me with a little more detail. You can get our email address at our website to send any pictures.

[@videosbystevebrown]

Do the rafter ties NEED to be connected to the top plate? Or can the rafter ties be moved slightly higher, connected only to the rafter on the lower third. Will not be storing anything on the rafter ties, just want a bit more headroom under the rafter ties in the garage. Thank you!!

[@gregvancom]

I can't provide engineering advice, but the 1/3 rule can be used.

[@emilyv5366]

What if you want to remove a perpendicular wall where ceiling joist overlap (due to too short joists that they staggered throughout the construction on perpendicular walls)? That wall (along with another staggered hallway wall) hold up these two sets of joists where they meet. Would you need a load bearing beam??

[@gregvancom]

Send me a picture, for more information and you can get our email address at the website. It's difficult for me to tell what you're doing, but you could also provide me with more details instead of a picture.

[@joegags6867]

I have the same situation what was the answer

[@nicholash8021]

Not sure I would using blocking between rafters (particularly where the rafters meet the top of the walls as in this video) because I fear they would block airflow from the eves to the ridge vent, thus any cooling effects would be lost. Thoughts?

[@gregvancom]

The airflow for roof like this can usually come from gable end vents located in the wall framing above the ceiling or dormer vents located in the roof on top of the sheathing. If this didn't answer your question, please provide me with more details about the blocks you're referring to and how they could block airflow.

[@nicholash8021]

​@@gregvancom I'm speaking about soffit vents whose function would be eliminated if blocking is installed between the rafters where they meet the top of the wall. A continuous flow of air from the soffit (taking in cooler air) and up the roof to the ridge where hotter hair is sitting, seems to be a better solution as it will naturally cause air to move due to the temperature differential. It also works well for insulated attics where the path from the soffit to the ridge vent can flow even with a fully-finished attic and can cover every bay evenly, unlike dormer vents. If you've ever heard about ice dams forming because soffits are blocked by insulation, then it would be logical to think a permanent piece of wood blocking this air path would also be a problem, trapping heat and moisture near the eves. I'm not an expert, but I would at least use blocking that leaves a 1 or 2 inch gap between the blocking and the sheathing. For roofs without soffit screens, there is actually a product called Raft-A-Vent that fills this gap with something that allows airflow while blocking birds and other small creatures. Check it out. Love your videos by the way and thanks for sharing your ideas. They have come in handy when building my shed.

[@tyrobertson7034]

how do you go about hanging drywall when your trusses are 4' on center? Could you run 1X4 16" on center in the opposite direction on the bottom of the truss?

[@gregvancom]

I think the most drywall can span is 24 inches on center, so you would need to install another joist that ran parallel to the trusses, because there's a good chance the trusses weren't designed to support drywall and adding additional weight to them, could create problems. You could always check with a roof truss manufacturing company for more information.

[@franciscosanchez2753]

I was wondering can I lower the ceiling joist and nail them below double top plate on the studs to get more storage space and remove rafter ties and some how ad a stud below for support I have 12 foot walls and want to remove rafter ties so I can get more space for storage

[@gregvancom]

I've seen it done before.

[@davidchavez81]

If a rafter tie is just to keep walls from spreading apart, why not just use cables?

[@hoveredgirlheygirlhey8345]

I had a question my garage is 24x28 and I need to install celling joises can I over lap two 14 foot 2x6s in every rafter

[@gregvancom]

I can't provide you with structural engineering information, but can tell you that I've seen people do this before with reasonably fair results. However, I don't think a structural engineer would approve it.

[@Eastbaypisces]

Can u put a rafter tie on a lean to patio cover? Basically tieing them into the house exterior wall for more support

[@gregvancom]

I don't see why not.

[@Eastbaypisces]

@@gregvancom I have wood siding so I could just tie it into the wood siding stud behind it, what kind of fasteners would I need ? nails, screws??

[@VictorErol]

So, the difference between a rafter tie and a ceiling joist is nothing more than the thickness of the wood and the placement on center?

[@gregvancom]

In a matter of speaking, yes.

[@mohammada6472]

28x27 attic. can i use 12ft long 2x6 16 on center to support ceiling and storage above attic ceiling?

[@gregvancom]

I can't provide lumber sizes for something like this, but think you should use larger lumber.

[@benjaminmothulwa5914]

what is the differece be trussed rafter and construction of roof truss

[@gregvancom]

A truss is usually a roof framing component made made up of a few different parts, where a roof framing rafter is a single piece of lumber cut to fit. Most of the time you will refer to something as a truss or a rafter, but I'm not familiar with the term trussed rafter. Let me know if this doesn't make sense.

[@randallnelson6695]

So how do roof trusses fit into this? It was my understanding that rafter ties helped to keep the walls from leaning out or as you stated "... to create a stronger connection between the roof rafters and the wall framing plates..." It was also my understanding they are also used to hold the ceiling drywall. So I'm still not sure as to the difference between the two since it was my understanding that one (rafter ties) can be used for both. Not trying to argue but seeking more clarification. Another point of interest is how attic insulation would fit into this? Thank you for the videos. They do help explain these thing. Looking forward to the next one. Perhaps one on joist/beam spans and their tables. Thank you

[@Jay-tk7ib]

With trusses, the bottom cord is your ceiling joist, or tie. If joists/ties sit directly on top of the wall plates, and are spaces 16" or 24" on center, they're called ceiling joists. If they're spaced 48" on center, they are called rafter ties, even when they sit on top of wall plates (Anywhere in the lower 1/3 of attic space). Whenever they're placed in the lower 1/3 of attic space, including on top of wall plates, they're called rafter ties, and are spaced 48" on center. Rafter ties are used in garages, etc., and are smaller lumber than regular joists. As has been explained, you can add extra ties between the existing ties that are 48" apart, and then you can drywall it and have a ceiling. Whether you're using joists, or ties, they keep the walls from leaning out, and keep your ridge from sagging.

[@marioromero4152]

We want to take down a wall just like in the vid where the cricket is and I would like to know if I could contact you to explain more on what I'm talking about.

[@gregvancom]

Yes, go to our website and at the bottom of every page you will find a contact link.

[@efrainrios6259]

Do you do patio plans?

[@gregvancom]

No,. But I do plan on doing more patio videos in the future.

[@think4two]

what causes a joist to bow towards the foundation/ ground and crack ceiling?

[@gregvancom]

If it's bowing down or sagging, then there's a very good chance it's undersized. For example if it's a 2 x 6 18 foot long then it might've needed to be a 2 x 8.

[@electricsuitbatman]

Wet wood when 1st installed with the joists natural bow upside down. As opposed to being ALL bow end up.

[@mikeh9987]

Overload in sheer.

[@renatochiarella4750]

If your ties are every 22.5inches(all 2x4s with braces attach to the roof )on a 20x 20 garage. Could it hold 1/2 sheetrock?

[@gregvancom]

Drywall can be used for 2 foot on center spacing or with 22.5 inch space between joist or trusses.

[@renatochiarella4750]

@@gregvancom my house has 2x4s roof ties. I ended up adding 2x6 joists nailed to the roof ties because the 2x4s roof ties were dry and were splitting

[@renatochiarella4750]

@@gregvancom I also wanted to add some attic space...hope that will suffice?

[@Eastbaypisces]

What's the difference between span and length of a rafter?

[@whith5184]

the length is the literal length of the piece of wood. the span of the same piece of wood is from one support to the other

[@joeydelmarsjr.646]

can i remove rafter brace that is attached to a load bearing wall in the attic?

[@gregvancom]

Probably not. Remember, these boards provide additional structural support for the roof framing system. In other words, a carpenter probably wouldn't of wasted his time installing something that wasn't needed.

[@joeydelmarsjr.646]

@@gregvancom thanks. Is there way I can move it vertical instead crossed ? Move out of the way

[@studdruppo]

Do you need blocking between ceiling joists?

[@gregvancom]

You would need to check with your local building authorities to verify my answer, but I usually don't block ceiling joists shorter than 12 foot, but do install mid span blocks on spans longer than 12 foot.

[@studdruppo]

@@gregvancom ,thank you ☺

[@swade3485]

This seems obvious but can rafter ties end toe nailed on an interior wall and function the same way? Imagine an L, where each leg is a room and lets say rooms are 14 feet width. the rafter ties for the bottom _ where the two intersect land on top of an interior wall of the bottom of I. Does that serve the same purpose? i assume obviously so as i don't see how else that wall would be tied.

[@gregvancom]

I've seen something like it done with steel.

[@swade3485]

@@gregvancom i probably didn't explain it correctly. But assuming an l shaped house + rafters, you'll have an internal support wall at the L for the celling joist to tie external wall -> internal support wall at that intersection (since there will not be two external walls at the intersection). i presume the joist/ties there provide the same function to hold the external wall straight by being connected to the top of the internal intersection wall.

[@homebuildingandrepairs3122]

@@swade3485 Yes, ceiling joist will be used to prevent walls from spreading. It would be like two separate building put next two each other with joist running in different directions.

[@gavinhiggins2911]

He checked the span chaft lol me to

[@gregvancom]

Span charts are good, but not always accurate.

[@oddopops1327]

:-)

[@gregvancom]

:)

[@oddopops1327]

LOL :-)