How many bundles do I need?

[FPM]

I've never done a roof, so be patient. I have a 2 car free standing garage 20x20 with a low angle pyramid type roof. Can any one help me ball park how many bundles/squares I need so I can do a rough budget?

Thanks

 

[stikman56]

You'll have some waste with a roof like that, I'd guess 7 squares would do it and give you a few extra shingles.

 

[LXCam]

What are the measurements of one side. Width and height to the apex and what type of material do you plan on using. There is a higher waste factor when using dimensional verses a plain three tab asphalt shingle.

 

[Larryjones]

A square is a hundred square feet. 3 tab run three bundles to a square, dimensional roofing will likely run four bundles to a square. You also have to plan your starter course and the ridges.

 

[FPM]

Looking for basic 3 tab shingles. This is for my in-laws who are on fixed income.

 

[Plump]

Yep, what LXCam said. Area of a triangle is 1/2(base)(height). There are typically 33.3 square feet of shingles in a bundle.

 

[FPM]

This is the only pic I have that might help you with an image. The tbird is mine...

 

[LB-1911]

I've never done a roof, so be patient. I have a 2 car free standing garage 20x20 with a low angle pyramid type roof. Can any one help me ball park how many bundles/squares I need so I can do a rough budget?

Thanks

You need to measure it.

HIP ROOF CALCULATOR
http://myrooff.com/hip-roof-calculator/

 

[LXCam]

After looking at the pitch I'm thinking it's more like a 4 in 12. So if it is you'd need 4 square or 12 bundles and I'd suggest one extra for waste. Also being a three tab you can make the cap from the three tab if you don't want to purchase any. So two more bundles should cover that. Basically 5 squares should get ya done.

 

[matt_i]

Here's how I would approach it. If roof pitch 3:12 (easiest is to estimate with a framing square) then the low angle is inverse-tangent (3/12) = 14.04 degrees. Then take 11 (half of the width + 1 foot overhang) / cosine (14.04) = 11.4 feet. That is the length down from the peak to the eave. Now multiply * 22 (again 20' + 2ft worth of overhangs) * 2 (for 2 sides). 11.4 * 22 * 2 = 502 square feet. If 3 bundles per square, then 502/100 = 5 squares * 3 bundles per square = 15 bundles. I would get at least 1 extra bundle for overage (16), and you will need to think about the ridge cap shingles, they can be cut from the 3 tabs or bought as extra-thick purpose built caps. I would go for the latter, the caps on my house are cut from 3 tabs and visually failing while the architectural deck looks great.

 

[FPM]

Thanks guys.

 

[rburke65]

I'll bet by the time you are done you are going to be closer to the 7 square that stickman56 came up with.

 

[bcvickers]

Don't forget about a starter course all the way around the perimeter. They can be had in rolls though. I'd also check into whether or not your area is going to require ice and water barrier on re-roof. Some do some don't, for unconditioned areas.

 

[JerryB]

I am getting ready to re-roof my hanger and shop / office building. I simply used my 100 ft tape to measure the actual roof: Got up on the roof, hooked the tape over one edge, went up over the peak, and measured down to the opposite edge. Measured the length of the roof sections and did the same in all directions on both the main hanger roof and the section that covers my shop and office. Same with the porches.

Multiplied it all out and added up the results. This gives a very accurate figure. It also allows the underlayment, starter courses, ridge shingles and metal valley flashings to be accurately measured and estimated.

Since I will have to pay for delivery over a mountain road from the dealer about 30 miles away, I don't want to have to do it again, and also want to make certain my roofer has everything he needs.

Interesting is that another roofer (not the one I am going to use) gave me a quote based on using 20% more material than will actually be necessary. When I questioned his figures, he said something along the line of "It's difficult to accurately know the actual size." He had simply measured the building walls and guessed at the overhang and slope, then added whatever he thought he could get by with. Of course he was going to charge me for all the extra in his fixed price quote.

We will use 5000 square feet of shingles (150 bundles) for this project, and if previous experience is correct, we should only have between 3 & 5 bundles left over.

 

[Kpaige]

FYI properly done there is less waste factor on a dimensional shingle compared to a 3 tab. As we do with dimensional a and 3 tab make a book and run diagonal you use your cuts on the next row up doing this you also only trim one rake edge as the other is done as you run up. Some also call this a stair method.
3 bundles = a square 7 square is a good estimate but eave and rake measurements I could give down to the bundle of what you will need.

 

[Kpaige]

The area your in you will want to use ice shield. It is required here in MN on all structures now. Plus why not if you ever plan on heating it you will be happy you did. Do not use roll starter and if you cut your own make sure you cut to use the seal strip at the bottom or by starter with the seal at the bottom. This is to make sure your bottom row seals so the wind won't grab it and bend it up and snap it off. Make sure the nails are in the correct locations this is one of the most common mistakes and make sure they are seated correctly-to deep and the shingle will not stay on the roof to little and you will see every nail from the ground holding the shingle up.
It's funny everyone says it's just roofing or they are just roofers but we can frame build copper roofs etc but I have yet to find a framer that can roof correctly.

 

[Seppala]

Back in Oct. 2010 I did a total tear off of a 2 car garage, 22x20ft, 4 in 12 pitch roof. Used 3 tab shingles and nailed with a China Freight roofing nail gun. Of course felt paper was rolled out and installed first. I needed a iittle more than 7 square of shingles to do the job. That job kicked my then 57 year old ***. Never again.

 

[NUTTSGT]

That hip roof is going to create more waste than a regular gable roof. You'll also be needing some of those 3 tabs cut down for the ridges after the rest of the shingles are down.

 

[CNGsaves]

+1 for Ice & Water Dam underlayment for the entire roof in your climate. Strip roof down to bare wood and repair any faults before proceeding with underlayment. Nail down any loose boards, or replace with plywood sheeting as needed. Also plan for any upgrades in ventilation such as whirly bird or turtle vents.

For starter row, get the roll stuff from Menards and just put it on top of your Ice & Water Dam underlayment . . . . yes install properly with the tar sticky part at outer edge to seal your shingles down.

There will be lots of scrap but save your pieces and use on other corners as possible.

Don't cheap out and use 3 tab. Architectural comp shingles are what you should install as they look great and last long time. Buy matching color 3 tab shingles ONLY to cut down for ridge cap pieces.

Last recommendation, buy a gallon of tar and USE IT on all roof penetrations.

 

[rayra]

You'll have some waste with a roof like that, I'd guess 7 squares would do it and give you a few extra shingles.

too much for a 3/12 or 4/12 roof. 6 square ought to do it. The roof sheathing on a shallow roof like that ought be <520sq'. But we're talking about only a 3 bundle difference, might as well buy the extra and return what isn't used.

 

[bczygan]

Check your pitch inside and also measure your overhang.

As mentioned above, allow for starter course and cap shingles and wastage.

Plus it is always a good idea to have some spare shingles for replacement of damaged ones.

Bill