Roofing how-to guides.
How to measure a roof
Measuring a roof comes down to two things: the footprint of each plane and its pitch. Get those two right and every material count follows automatically. This guide walks through doing it accurately without guesswork.
What is a roofing square?
A roofing square is the single unit the entire trade estimates, quotes, and orders in. Once you understand it, every other roofing number — bundles, rolls, prices — falls into place.
3-tab vs architectural shingles
The two most common asphalt shingle types differ in weight, appearance, lifespan, wind resistance, and — importantly for estimating — how many bundles cover a square. Here is how to tell them apart and which to plan for.
Roof waste factor explained
Waste factor is the extra material you order beyond the bare roof area, to cover cuts, valleys, and mistakes. Leaving it out is the most common — and most expensive — estimating error, because it leaves you short mid-job.
How many bundles of shingles do I need?
Once you know your roof in squares, the bundle count is straightforward arithmetic — but the shingle type changes the answer, and the field shingles are only part of the order.
Roof pitch explained
Pitch describes how steep a roof is. It drives how much surface you are actually covering, which materials you can use, and how safe the roof is to walk — so it is worth understanding properly.
Starter strip and ridge cap basics
These two accessories are easy to forget and easy to under-order, yet they protect the most vulnerable parts of the roof — the edges and the peaks. Here is what each does and how it is counted.
Roof underlayment types
Underlayment is the water-resistant layer between your roof deck and the shingles — the backup that keeps water out if anything gets past the surface. The type you choose changes how much you order and how the roof performs.
Estimating valleys and complex roofs
Valleys, hips, and dormers are exactly where simple calculators break down — and where measuring plane by plane earns its keep. Complex roofs are not harder to estimate, just made of more pieces.
Metal vs asphalt roofing
Metal and asphalt are the two most common steep-slope choices, and they differ in nearly everything that matters for estimating: how they are counted, what slopes they suit, how long they last, and what they cost.
Reroofing over vs tear-off
When a roof reaches the end of its life you have two paths: lay new shingles over the old layer, or strip everything to the deck first. The choice affects lifespan, warranty, cost, and what your code allows.
Do I need a permit to reroof?
Most reroofing work needs a permit, but the details are set locally and vary widely. Here is the general picture and, more importantly, how to confirm the rules for your address.
How long does a roof last?
Roof lifespan depends mostly on material, but installation quality, ventilation, and climate decide whether a roof reaches the top or the bottom of its range. Here is what to expect and what moves the needle.
Drip edge and flashing basics
The metal edges and joints of a roof are small line items on an estimate but outsized in importance — they are what keep water out at the most leak-prone spots. Here is what they are and how to account for them.
How to estimate a roof for shingles
This is the complete walkthrough that ties every other guide together — from a tape measure to a full material list you can take to the supplier. Follow it in order and you will not miss a step.