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ABOUT ROOFING

(written 2023-02-04, updated 2023-04-10 to add more definitions)



lots of roof types:

• shingle
• tile (flat and curved types) (HEAVY, requires specially-built house to support the weight!)
• metal (holds up well, but noisy during rain/hail) (also HEAVY!)
• white goop on a flat roof
• thatched like they did in the 1400s (thatching = made of straw)
• etc...

I'm going to talk about shingle roofs.


how to tell when needs replaced:

• asphalt wears off
• gravel falls off
• there are bare fiberglass patches (looks "sparkley" under a flashlight)

About the material!

• shingles = made of fiberglass fabric, dipped in asphalt, coated in gravel
• shingles come in a bundle or a square:
  • bundle = 33 sq. ft. of roofing
  • square = 100 sq ft

the roof layers go like this:

• house frame (on bottom)
• plywood sheets
• underlayment
• shingles (on top)

A shingle roof will last 20-30 years (assuming you take good care of it).


NB: they might offer to layer new shingles over old, don't do it. (b/c is crappy)
Instead, rip off everything down to the plywood, check the plywood and spot-repair, put on new underlayment, and put on fresh new shingles.

Ask them to leave the extra shingles for you to keep.
Heavy storms will bend them, or even rip off some of them, and you can easily spot-repair (if you have extra shingles). Take the new shingle up to the roof, along with a bottle of caulk or roofing tar, some fine gravel or sand, and some roofing nails.

• if the old shingle is still mostly ok, just glue/nail it back down.
• if the old shingle cannot be salvaged, carefully remove it, and stick a new one in there. use the caulk/tar and some nails.
• exposed nail-heads can cause roof leaks, so either hide them under other shingles or cover them with tar and gravel.

Get your HOA's approval before re-roofing, because sometimes they might not like the color.


options for replacement

• three-tab shingles = old, not used anymore, thin and easy to break in high winds
• architectural shingles = the sexy new thing: stiffer, heavy-duty, more layers
  • they are also called dimensional shingles

• 30-year vs 50-year warranty
  • might need to use specific underlayment to not void the warranty

• facsia = wooden board running along underside of the very edge of the roof, needs frequent sanding/painting to avoid peel + rot
• drip edge = 90-degree metal piece, goes between lowest shingles on edge and the facsia board to help stop rain from getting under shingle
• eaves = the part of the roof that overhangs the edges of the house

• underlayment
  • synthetic underlayment = waterproof rubbery plastic slabs
  • non-synthetic underlayment = felt soaked in tar, lets the roof "breathe" (less chance of mold for the plywood underneath), less waterproof though (put the shingles on before it gets rained on!)

• ice/water barrier
  • needed above all eaves, or only in the roof valleys?

a note on attic ventilation
attics need ventilation. they have weird temperature conditions that are different from the outside weather, this causes condensation and moisture to form. if there are no vents, or improper vents that make the wrong airflow, you will get mold.
attics get hot, and hot air rises, so air in the attic will try to move upward. you want the attic to be able to pull fresh air from down low, and vent out the top.

types of attic vents

• gable vents = go outside your house and look at the walls near the peaks of the roof. a gable vent looks like a square of window shutters. if you have gable vents, you should have at least one on each side of the house, to allow wind to flow through the attic.
• ridgecap vents = DO NOT COMBINE WITH GABLE VENTS, causes bad airflow patterns and retaining moisture. good to use if you DON'T have gable vents. they chop a long thin slice out of the roof, running along the peak edge, about 5 inches wide, and attach a vented ridgecap. very good at releasing the hot air from the attic, because they go right at the top where all the hot air is. sometimes they might get clogged with leaves, go on your roof and clean them out.
• turtle vents / box vents / spinny whirlygig vents / etc etc etc = they punch a hole in your roof and attach one of these, to allow airflow but keep out rain. works fine as a vent, but makes the roof slightly weaker and more prone to leaking in that area. if you are relying on these, you need multiple of them.
• soffit vents = go under the eaves and look up. the flat wooden underside is the soffit. there should be holes leading into the attic, those are the vents. soffit vents are the intake vents, and are required for the output vents (gable, ridgecap, etc) to work properly. if there are no soffit vents, you have a problem and should put some in.
  • they should have wire mesh to stop bugs/birds/bats/mice?
  • is there another equivalent (low vent for intake) you might have instead?