HAP Adjustment

dave owens

I'm a finish carpenter who has been saddled with a roof from hell (I think its known to the pro roof framers as a bastard roof......an apt title if ever there was one) Anyway I ran the numbers through an online calculator and everything kind of makes sense, except for the HAP adjustment- (11' 11 5/8")
I know HAP is heel above plate but what is the number at almost 2 feet saying I should do to get my overhang to work

K2

More info please. Welcome to the site..

TurnkeyConst

What are all the numbers you put into the calculator and their relevant places? Rise/Run, Rafter Depth, amount of overhang, bldg width from wall to wall, and desired pitch? Then maybe I could give you some help.

dave owens

Thanks for the welcome and any help you can provide. The building is an addition 16' 2 1/2" from the main house and 24' 6" long. it wraps around one corner of the house just 42.5" so basically a very large porch roof. The major pitch is 2.5 the minor is 5

dave owens

Oh and 2x12 rafters. which seems like overkill to me but what do I know

dave owens

And, the vital piece of info. the overhang is 5"

cleveman

I always refer to HAP as height above plate, but I suppose heel works as well. Why don't you draw the thing out on a piece of paper first, then lay out a rafter? If you have a spacious slab somewhere, draw the whole thing full scale and put your rafter down on it.

Gold Tie

figure the overhang (minus fascia thickness and adding sheathing thickness) as a run for both pitch's and ask for the rise on each pitch. The difference in rise (subtracting the short number from tall number) is the difference in standing height (or hap?). The steep pitch is the taller stand.

The hip's standing height will be that of the steeper pitch and placed out of the corner (towards the steeper pitch) on the run of whatever the rise difference is.

I don't have a clue what the 2 foot number is. With a 2 1/2 pitch difference, and low one's at that, there should only be about an inch difference on stand heights.

Hope this helps and isnt to late!!!

Joe Carola

You haven't given all the dimensions. You say that you have a 16' 2-1/2" run with a 2.5/12 pitch and the other side that wraps around is a 5/12 pitch.

If that's the case the 5/12 pitch side has to have a run of 7' 10-3/4" to the outside of the plate and adding 5" overhang will be 8' 3-3/4" including the overhang.

Is the porch something like this? Maybe the opposite side. What is the length of the return side on the 5/12 side.

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Joe Carola

dave owens

Thanks Joe. That dimension is the 42.5". Where you have 8' 3 3/4" this should be 4' 8" and where you have 24' 11 1/2" this is actually 24' 6". I stuck the hip on the corner and went with a 15 inch soffit on the 2.5/12 side and 8" on the 5/12, to keep facia consistent. I also raised the heel on the 5 pitch side by 1/2". That seems like its going to work but god only knows what will happen when I get to the return section, when the pitch is going to over 12 probably. Back to gazing skyward like a monk with concussion I suppose.

Gold Tie

15 inch soffit sounds alot better than a 5 inch!! Glad you got it done!

Sorry, I guess I mis-understood the original question. I thought you were asking how to get the soffits at the same height and distance out so you did'nt have to have 15" on one side and only 8" on the other.

bee1706

If your finishing this project, your numbers should be figured from the lower side of th hip, and therefore the rafters and the lower hip should meet. I think yoiur going from the top of the hip to the lower side of the hip, and your close?