Gypsum vs Plywood Ceilings in Spanish Town: Cost, Heat and Damp

Use gypsum board for indoor rooms under a roof that doesn't leak and has air moving through it. Use plywood where a ceiling might get wet now and then, or outdoors under a verandah, and pick the grade for the job. Neither one fixes a bad roof, so sort the roof first.

Key Takeaways

• USG's product information describes the gypsum core of its board as noncombustible.
• Unprimed half-inch gypsum board can sag on a ceiling when high humidity and heavy water-based texture meet framing wider than 16 inches apart or a roof space with no airflow.
• Structural plywood generally stays sound after a wetting, but it can rot if it stays damp for a long time.
• The West Indian drywood termite is found in Jamaica and feeds on wood, which matters most for a plywood ceiling.
• An outdoor or verandah ceiling in plywood needs an Exterior-rated panel, not an Exposure 1 or CDX sheet.

How do gypsum and plywood compare?

Gypsum wins on finish and fire. Plywood wins on standing up to the odd wetting. The rest depends on the roof above it and who is doing the finishing.

On fire, the board maker USG's product information for one of its gypsum panels describes the gypsum core as noncombustible, wrapped in paper faces. Plywood is wood, so it burns.

How does each one cope with heat and damp?

Gypsum is the fussier of the two. It needs a dry, ventilated roof space above it and framing close enough together to hold it flat.

National Gypsum's September 2026 guide to humidity and gypsum says proper ventilation, or a conditioned attic, must be provided to remove moisture buildup above gypsum board ceilings. The same guide warns that high humidity, combined with heavy water-based texture, can make unprimed half-inch board sag if the framing is wider than 16 inches on centre or the space has no airflow. It also says paper-faced board can grow mould when the paper stays damp above 70% relative humidity with no air moving, and that a vapour retarder may be needed behind gypsum in an exterior ceiling.

Plywood is less fussy about the air around it. APA, the engineered wood association, says on its frequently asked questions page that wood in a finished building normally settles at a moisture content of 6 to 14%, where moisture has a negligible effect on its strength or durability. The risk is wood that stays wet: decay and mould can follow if the moisture content sits at roughly 20 to 25% or higher for a long stretch.

If what you really want is a cooler room, that's a question about the roof space, not the board. Air moving under the roof and a dry space above the ceiling help either material, and gypsum depends on them.

What about termites?

They are the strongest argument against plywood overhead. The California Department of Food and Agriculture's 2025 profile of the West Indian drywood termite lists Jamaica among the places it is found. It calls the termite a wood-feeding pest that is generally restricted to buildings and furniture, and says old, historic buildings are especially vulnerable.

So before you put new plywood up in an older house, have a pest control company look at the timber that's already there. It's far easier to deal with before a new ceiling closes it in.

Which one survives a roof leak?

Structural plywood, in most cases. APA says structural plywood used in floors, walls and roofs is made with water-resistant adhesive and generally stays structurally sound after a wetting, even if the surface goes rough. A thin ceiling panel that isn't a structural grade may not be made the same way, so check what you're buying. If a gypsum panel goes soft or sags after a leak, plan on cutting it out and patching it, which means taping, filling and repainting the repair.

Two cautions on plywood. APA's plywood guide says a panel's bond rating describes its glue and doesn't stop fungal decay, so a ceiling that keeps getting wet will still rot. And it says Exposure 1 panels, including CDX, aren't made for permanent outdoor exposure. Exterior panels are.

Either way, the leak is the real job. Our guide to fixing a leaking roof covers finding where the water actually gets in.

What drives the cost of each?

With gypsum, the finishing. The board itself is only part of the job. Joints need tape and compound, then sanding, priming and paint, and a ceiling shows every flaw. National Gypsum's ceiling questions page suggests a Level 5 finish on ceilings, because sunlight from windows and light from fittings can show up the joints. It also recommends sag-resistant half-inch board when framing is 24 inches apart or a water-based texture goes on, so wide framing can change which board you buy.

With plywood, the grade. A verandah needs an Exterior panel, and indoors you still paint or varnish it. There's no taping and filling, but you see the sheet joints unless you cover them with strips.

The fair comparison is the whole ceiling, finished: board, framing, fixings, finishing materials and labour. Ask for both options priced on the same room before you decide.

Which should I use in each room?

Match the board to what the room puts it through.

Planning a ceiling job in Spanish Town

Spanish Town is the capital and largest town in the parish of Saint Catherine, and it was the capital of Jamaica until 1872, according to Wikipedia's Spanish Town entry. If you're working on an older house there, check the roof timber for termites before you choose a board.

Write the list from the room, not from memory: the ceiling's length and width, how far apart the joists or battens are, which board you've chosen and how you'll finish it. Then add the fixings and the paint, which our fasteners and fixings and paint and finishes departments cover. For the board itself, call (876) 926-3611 and ask what the store has before you travel.

Malcolm's is at 44-46 Slipe Road, Cross Roads, Kingston, and a call-ahead order can be ready to collect. Our Spanish Town page has more for customers coming from Saint Catherine.

Frequently Asked Questions