Pentice Roof

[Brian_Weekley]

I'd like to install a pentice roof over the swing out doors I'm planning to install on my barn.  Any suggestions for angle and design?  It's hard to find some good examples of construction to look at.  Not sure about the best method for attachment.  The bottom can be screwed to the tie beam, but I'll probably have to use carriage bolts through vertical strapping, insulation, and siding (wrap and strap) for the header.

[kderby]

I had no idea what a Pentice roof was.  I clicked on this thread and vavoooom!  Thank you for the education!  Now I hope someone has a brilliant answer to your inquiry.

Kderby

[Satamax]

Brian, one trick would be to make it wider, and have supports. But you can always attach to the tie beam, and if you want to go big ish, may be use some nice looking chains, atached to the rafters above. Just an idea.

[giant splinter]

Brian,
Im wondering what your plans are for the open area above the tie-beam is it possible to add another collar tie just above the tie-beam to support the weight ........ if your all closed up or doing a loft door or something of that nature I would bet Jim Rogers could figure out something to support the Pentice / eyebrow in a timber frame style connection.

[Brian_Weekley]

I'd really like a simple looking, Dutch-barn type of pentice roof over the door.  No chains, posts, or big brackets desired.  There is a collar tie and window near the peak (just out of view in my drawing).  Unlike dutch barns that typically have horizontal siding with vertical studs that the pentice could easily be attached to, mine only has vertical siding between the tie beam and collar tie.  Eventually, I'll add 2" rigid foam, vertical strapping, horizontal strapping, and cedar shakes.  I'm thinking at the vertical strapping stage, I would attach the pentice roof.  The upper header could be attached with carriage bolts that go all the way through and secured with washers and nuts on the inside of the siding.  I'm really trying to find a good picture of the pentice frame contructions and curious if anyone has built something like this on their barn.  The roof sits out much further than a cover over a sliding barn door. 




   

[thecfarm]

Lots of them around here. Never knew that it was a pentice roof. The ones I see are on old barns that cover the track for the door. That would be a wheel on a track. The ones I see start on one edge of the door and goes to the end of the barn.

[Jim_Rogers]

Pentice roof were place over doorways for one simple reason. To keep the ground near the sill at the doorway dry from rain water. You see with these large Dutch barns the ground was banked up against the sill so that the wagon could roll up the dirt ramp and into the barn. If the ground was wet then the sill rotted.

There are several historic ways to support a pentice roof.

One is by placing an "outrigger" timber right through the tie beam to support it, like this:



 

The above drawing can be seen in a free download from the guild site.
The caption reads: "Many Dutch barns had cantilevered pentice arms or outriggers mortised full-size through the gable anchorbeam. Four or five of these supported the pentice pate and rafters."

Also:



 

This drawings' caption reads: "Many end anchorbeams have telltale mortise, but only one example of this type has been found with all pentice parts intact on a 44x45 barn that originally stood in Berne, NY. Though the 3x3 tenon 5 in. long would seem to be undersized, it worked for over 200 years."

When I visited the Wemp barn, pictures in my gallery, I saw this pentice roof:



 

From the inside I saw a very large through tenon that was wedged just over the door hinge:



 

When we did a pentice roof over a shed opening a few years ago we did this:



 

And after the roofing was put on like this:



 

And the long view:



 

This long pentice roof covered the sliding door track whether or not of the door was closed or open.

I hope this has helped you some.

Jim Rogers

[Brian_Weekley]

Thanks, Jim.  That's exactly what I was looking for.  That's a much simpler solution and the tenon/wedge would look far better than nuts and washers!  It's certainly simpler when you're working with plain siding.  In my case, the added exterior insulation and strapping does complicate the attachment a little bit.

Cutting mortises through the center of the tie beam is the best place since the wood is under the least tension and compression at that location.  Is there a rule about how big of a mortise you can safely remove from the center of the tie beam?   In your example, were the horizontal outriggers through-tenoned in the tie beam as in Jack's drawing, or were they attached in a different manner?  What size outriggers/tenons/tie beam in that case?

Thanks, Brian

[Jim_Rogers]

I've got to run out to a meeting I just found out about.

I'll post more info later on.

Jim Rogers

[Jim_Rogers]

Thanks, Jim.  That's exactly what I was looking for.  That's a much simpler solution and the tenon/wedge would look far better than nuts and washers!

I was going to mention to you that through bolts with nuts and washers isn't the best when one side is in the heated environment and the other side is in the cold. The moisture will condense at the cold point and if that's inside the wall then that's were the water will collect and could cause rot.

Cutting mortises through the center of the tie beam is the best place since the wood is under the least stress or compression at that location.  Is there a rule about how big of a mortise you can safely remove from the center of the tie beam?

I don't know if there is any "rule" about that but you should try and calculate the load of the roof, including snow load and try and size things so that it will be able to hold up that load.

In your example, were the horizontal outriggers through-tenoned in the tie beam as in Jack's drawing, or were they attached in a different manner?

 

I couldn't remember so I had to look at the model in my drawing program. It appears that we ran 4x4's over the tie beams to hold the awning/pentice roof up. And the plate was slide in between the pentice beams. I never worked on that part. The customer did it himself.

His tie beam were kind of small and I didn't want to cut holes/mortise in them. So that's the solution we came up with. I think he may have put some decking over the pentice beams to create a loft area. I'm not sure I haven't been back there for a while to see it.

Jim Rogers

PS. as this was a small tractor shed, he wanted to have as much natural light in as he could. So we lined up the window in the door so that even if the door was open the window in the wall was in the same place so that the sunlight on that east side would shine through the two windows.
The black piece in the above drawing is suppose to be the sliding door track attached to the outside of the tie beam, outside of the siding.
And I think he resized the window above the door from what I have shown to the smaller transom sized window.

[Brian_Weekley]

Thanks for the info Jim.  I'm still deliberating on my options (and over-thinking everything as usual)!

My "maine" consideration is that I want the exterior look to be consistent with a Maine/New England style barn.  Of course, this is a little subjective as there are many styles and variations.  When I think of a Maine barn, I typically see gable end doors with a transom window on top.  A lot of them are shingled and have nice trim details like roof returns at the eaves.  In my mind's eye, a Maine barn would look something like this:



Back to the pentice roof...Unlike a small roof protecting the track on a sliding barn door, the pentice roof juts out much further and is typically found over swing-out doors on Dutch barns.  However, I believe the true Dutch-style barns are typically found south of Maine (NY, NJ, DE, PA).  I love the look of sliding barn doors, but I've been leaning towards hinged, swing-out doors instead.  Mainly because if I insulate the building, I think I could build better insulated doors and seal them better than the sliding ones.  In addition, since there is no "people door" in my little barn, the hinged door would be more practical and easier to use then a sliding one.  I can't say that I've actually seen any pentice roofs over doors on Maine barns, but I have seen a lot of large, flared-out, shingled overhangs over the doors (mostly over sliding doors).  I don't know what these are called, but they are pretty cool too.  Something like this:



Since I haven't framed any windows yet or cut holes in the siding for them, I still have a clean slate for my window layout design.  If I install a transom window over the door, the pentice roof may look out of place.  Maybe just a small roof/drip edge over the door with a transom window above it?  Maybe none at all?  What to do, what to do...  Unfortunately, since I won't be finishing the exterior until next summer, I have all winter to obsess about it.  You'll probably have to wait that long to find out what this crazy person ends up doing!