How to Frame a Small Hip Roof

Hi Guys,

Does anyone have any practical advice for framing a small hip roof?

I'm building a 9' x 10' shed and I've read a bit about hip roofs, but they seem tricky to build. Is there a simple and practical way to do it?

On a related note, I was planning to install soffit vents and a ridge vent in the small ridge.

The ultimate goal over the next year or so is to completely finish the inside and use it as a garden office/studio during the warmer months.

Thanks!

That's a little tricky, we don't know what your skill level is.
From the sky looking down all the hips are at 45 degrees. So you draw that plan with 2 trusses or rafters in the center. If your shed is exactly 9ft the truss would be 5' 4" from the end of the shed.
Then the two hips meet in the middle and extend over the corner.
You will have to decide the pitch you want to build.

Tools you will need is 2 ft square, quick square and a good immagination.
I will leave it for you to ask more questions.

Easyer woud be to order engineered trusses, they come with a layout for placing them.

I guess I will ask why you want a hip roof on your shed? Will it match your house better? If so you might want to select the same pitch as on the house?

The link Neal suggested shows what a hip roof looks like and I know in some areas they mislabel gambrel roofs as hip roofs.

Before we get into how to do a lot of compound angle cuts could you attach a link to something that you are trying to get the look of on your shed.

First of all, thanks for the link. It really helped clarify part of the process.

I'll post my questions first so you don't have to read all the other stuff if you don't want to.

1. What size rafters do I need for an 8/12 pitch roof? Are 2 x 4s ok?

2. I read somewhere there needs to be a minimum height between the top of the birdmouth cut and the top of the rafter. I think it was either 1-1/2" or 2". Do you know anything about that?

3. I'm planning on building the ridge with side common rafters on the ground and then putting it in place since the ridge board is only 1' 1-1/2" long and then attaching the front and back common rafters. Do you think that's a good idea?

I have little experience framing other than basic stuff, which this is not. However, I am very meticulous and detailed and I don't mind going slow.

I want a hip roof so that it matches the hip roof on the house which has a 4/12 pitch, I believe. However, I'd like an 8/12 for the shed because it's more aesthetically pleasing. I've included an image of the shed I'm building.

Neal, you said the rafter should be 5'4" from the end of the shed. Was that a typo? I calculated 4' 5-1/4" after taking into consideration the width of the ridge board. Based on that I have the common rafters and ridge board laid out.

Here is approximately what I'm going for only my shed is 9' wide x 10' deep.




Thanks for all your help so far!

On that small of a shed with very little overhang 2x4 is all I would use for all the framing including rafters.

Something to think about on a small building is scale. Going with heavy framing will make It look out of scale.


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Are you planning on the doors opening in or swing out? You will loose a lot of storage space if the doors open in. Just my:2cents:

As to the build yes start with the 2 commons up to the ridge on both sides then the single hip common on each end, then the 4 hip rafters. This will define the lines. Then fill in with the jacks. Once you get the setting right for the compound angle. The only thing that changes will be the length. Cut your birds mouths just as deep as you need to get a flat 3.5 wide. If you have a drafting board or cad it helps to do a layout.


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Type O, yes.

If you are using the shed for an office, you will want to insulate, so you might consider 2x6s just for that reason. that would allow insulation and venting shoots above the wall.

I hope you put headers over door and windows to support the roof.

The compound angle that Bud talks about can be made simple, once you have figured out the angle of the 8/12 plum, seat and hip, you cut everthing with the skill saw set at 45. You just have to know when to add 1 1/2 or 3/4 inches to the length to allow for the cut.

If you want to use a non compound miter saw, your best to make the cut with a skill saw first and then use that to set the compound saw
We just do it all with the skill saw.

As you will need a ceiling anyway I would build trusses for the two and the same for the two end jacks.
The other way you could do it is to build a center truss the other way with a flat top and then just use jacks on the side.
[ame]https://www.youtube.com/watch?v=b--B4HR_xO0[/ame]

This the sqaure the industry uses most.
http://www.stanleytools.com/xhtml/literature/stanley_quicksquare.pdf

Wow! Thanks everyone for your advice and suggestions. I'll need some time to digest all this.

Yes, I've ordered patio doors that swing out which were hard to find at a reasonable price.

Yes, scale is very important for this project, but I have a question. Once the shed is finished, how will the size of the roof rafters affect scale? They will be covered and not visible, right? Or, am I missing something?

You are correct except how you finish the rafter tails into overhang and then they can be cut down to any size you want. I really think you need a plan on paper. I'm a guy that builds a lot out of my head and I would do a layout of your shed if I was going to build it.

Are you going to have a flat ceiling inside. On such a small building I think you could push the ceiling up and do a type of collar ties and give appearance of a larger space. Like a tray ceiling.


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Ok, now I understand about the rafter tails and scale. Thanks for pointing that out.

I was thinking about a raised ceiling too, but no idea about building it properly. What distance from the ridge should I place the collar ties?

I am working on some drawings before I start building the roof. I've spent much of this morning trying to figure it out. It seems really crazy at first, but it starts to make sense after a few hours!

There are a few dictates for the overhang. You don't want the gutter to hide the trim over the doors and windows. So on an 8/12 if the overhang is 12 inches it will drop 8" plus the depth of the birdsmouth and about 1" for soffet. Truss companies can change that as they don't have a birdsmouth and can raise the roof line at the wall. They call that a raised seat cut. With rafters you you just have to shorten them to fit.

I think the rule of thumb is 1/3 the way up the rafter to the bottom of the collar tie. In such a small building that is actually over framed due to its scale I would think you would be fine going half way up.

To Neal’s point are your walls full height like they would be in a home with 8’ ceilings. I don’t know if you are planning gutters or not and I might even skimp on his rule of seeing the full door trim in order to bring the height down in order to keep proportions correct to scale. You do need to be high enough that a normal out swing door clears the soffit.

By bumping the ceiling up you can maintain a nice ceiling height inside and keep it from looking too tall for the small footprint.

My brother in law built a few sheds where he tried to make best use of the materials and inside storage space so he made his walls to suit a full 8’ sheet of T1-11 siding. His sheds are 10x10 and to me look overly tall and out of proportion. The commercial ones they sell all have special short doors they build just for the sheds to lower the scale.

Not sure about max birds mouth cut, as the only times we cut our own rafters is for vaulted ceiling much like you and Bud are talking about and then we use 2x10s to allow for insulation and air flow.

Here are 2 images of the final look I'm aiming for. It does look a little taller than I would like, but I'm also limited by the space where I'm building in terms of the local zoning by-laws. Anyway, it's been a very intense learning process up to this point.

The door header is made up of 2 2x8s 73" long with 1/2" plywood sandwiched between them and the window headers are 2 2x6s 60" long with 1/2 " plywood sandwiched between them.

The top plate is exactly 8' from the base, so I guess that means the walls are 8' high.

I am planning gutters, but I need relatively small ones which I can't really find. I am considering buying painted sheet metal and making my own gutters by bending it on a press, but that's going to be a big project in itself so it's one of the last things I'll be doing.

In terms of the collar ties, is it ok to do those last, once all the rafters are up?

Finally, with respect to the insulation and air flow, can I insulate the top of the ceiling, and leave everything above that empty so that the attic temperature remains the same as the outside temperature? That's how my house is built. If that works I can use 2x4s for the rafters.

It looks good to my eye. Yes on a larger building the reason for the Collar ties or the ceiling joists are to keep the walls from going out when there is a big load on the roof. With your almost square building and being small in foot print the hip rafters direct all the load out to the corners and are actually pulling the building square by the corners. The jacks are just something to hold the roof sheeting. You really wouldn’t need any joists or collar ties if you didn’t want them IMO. Are you planning on heating and cooling the shed? If not I don’t know if I would put any insulation in it at all. Your ridge is so short I don’t know how much opening you will have in it for ridge vent and if it will be enough for the area of the roof. Others might have some ideas to offer you on that.
What program did you use for the design? Looks really nice.

Collar ties in the upper third hold the roof together in high wind situation. rafter ties are in ther lower third to hold the walls together everyday.

Hip roof with out ties will put extra amount of weight at the coners.

The word office says insulation to me.
With out ties the rafters have to more than 2x4 for insulation, then the roof would be straped with 1x4 or 2x4 for venting as each jack would stop air flow.

For the outswing double doors. I would plant 2 6x6s and add 3 ft to the front of the roof to protect them from the rain.

Yes, it will definitely be insulated. I'm planning a little heating with electric heaters, but I don't have any plans to cool it for the moment.

I will start a new thread regarding the venting and see if anybody has ideas.

The program is Real Landscaping Pro 2013. This is the trial version, but the full version is only about $100. It's really an awesome program for the cost. I'll purchase the full version once I have a little more time to play around with it.

So, let's say I go with a flat ceiling. Do I put the joists across the building running parallel to the doorway or across the long side of the shed or both? Do I fasten them to the top plate or the rafters or both? Do I need collar ties as well?

I don't understand when you say "each jack would stop air flow". Does that mean the jack rafters will stop air flow? When I look at a diagram I don't see how that works.

The extra roof to protect the door is a good idea but I don't think I'm ready to go that far on this particular project. The door will be a steel double patio door so I hope that can withstand the elements on its own.

If you go with the flat ceiling the ceiling joists will both connect to the rafters and the top plate and the insulation will fill the joist cavity. You wont need collar ties. In a small building I don’t know if you will want a trap door or what to get in there. If it was mine and I wasn’t going to be out there in below freezing weather I think I would just insulate the ceiling with foam sheets and drywall over it. As to a vent with only a foot of ridge I wouldn’t mess around with ridge vent and I would put a single roof vent on the back side of the shed

I will check out Landscaping Pro. I do all my work on Autocad Inventor but looking for something quick and simple for home use.