Two layers against one
A three-tab shingle is a strip of a single thickness, with two slots that form three tabs. The whole roof has the same thickness, and each tab is a small flap exposed to the wind.
An architectural shingle is laminated. A top layer, cut into irregular blocks, is bonded at the factory onto a full bottom layer. Where the two layers overlap, the shingle is much thicker. No slots cut through its visible part.
Single or double layer construction is the clearest difference among the types of shingles on the market. It explains almost everything else.
Wind resistance
Wind tears off a shingle by lifting it from the bottom. The more flexible and light the shingle, the more it flaps in the wind, and the sooner its adhesive strip gives way.
The architectural shingle starts with two advantages. Its weight keeps it flat. Its stiffness keeps it from folding when a gust gets underneath. Manufacturers generally give it a better wind rating than the three-tab. The exact rating is on the product sheet.
Installation matters as much as the product. The number of nails, their position on the nailing line and the time the adhesive strips had to seal decide how well the shingle really holds. A shingle nailed too high holds poorly, whatever its family.
Appearance
A three-tab roof shows a repeated pattern, with slots lined up every other course. The slightest crooked course shows, as does a bump in the decking.
The architectural shingle breaks up that pattern. Its blocks of different widths and its shade variations create shadows that recall wood shakes. The roof looks thicker. Small unevenness in the decking gets lost in the texture.
When the three-tab still has its place
The architectural shingle has become the usual choice, but the three-tab is still useful in a few cases.
- Repairing a three-tab roof. To replace a few shingles, the same type goes in, or the patch shows.
- Covering a shed or a detached garage. Budget often comes before appearance.
- Keeping the original look. On some houses, the flat finish is part of the character.
Frequently asked questions
Are architectural shingles worth the extra cost?
Yes, in most cases architectural shingles are worth the price difference. The gap in material cost weighs little in a bill where labour, tear-off and accessories count for a lot. In exchange, the roof holds better in the wind and ages more slowly.
Can architectural shingles go on a roof that had three-tab shingles?
Yes, architectural shingles can go on a roof that had three-tab shingles, during a full replacement. They are heavier. If the roof frame is in doubt, have it checked before installation. If someone offers to cover the old roof rather than tear it off, the decking will stay hidden. Ask how its condition was checked.
Do laminated and architectural shingles mean the same thing?
Yes, laminated and architectural name the same two-layer shingle. You also hear dimensional shingle. Product line names change from one manufacturer to another, but the construction is the same.