Does drywall go over New Brunswick lath?

In most NB renovation scenarios, yes — drywall goes directly over new framing after the lath is removed, not over the lath itself. Drywalling over existing wood lath is technically possible in limited situations, but it's rarely the right approach for NB homes and comes with real drawbacks worth understanding before you decide.

Why Lath Removal Is Usually the Better Path

Older NB homes — and there are plenty of them, particularly in Fredericton, Saint John, and the older neighbourhoods of Moncton — were built with wood lath and plaster as the standard wall system. Three coats of plaster over narrow wood strips was the norm right through the 1950s and into the early 1960s. When that plaster is crumbling, cracked beyond repair, or you're opening walls for electrical or plumbing upgrades anyway, stripping back to the studs is almost always the smarter move.

Removing lath and plaster gives you full access to the wall cavity, which matters enormously in NB's climate. You can inspect for moisture damage, mould, and rot — all common findings in older Maritime homes. You can upgrade insulation properly, run new wiring and plumbing to current code, and install a continuous poly vapour barrier on the warm side of the insulation before drywalling. That vapour barrier is critical in NB given our 30-50% annual humidity swing between dry winters and humid Maritime summers. Skipping it because you drywalled over lath is a long-term moisture problem waiting to happen.

When Drywalling Over Lath Might Be Considered

If the plaster is structurally sound and firmly attached, and you're doing a purely cosmetic refresh without touching the wall cavity, some contractors will skim-coat the existing plaster or apply ½-inch drywall directly over the lath and plaster. This avoids the mess of plaster demolition, which is genuinely significant — lath and plaster demo is dusty, heavy, and labour-intensive. The tradeoff is that you lose roughly ¾ to 1 inch of room depth, your electrical boxes and window and door casings all need to be extended, and you're covering whatever moisture or insulation problems might be hiding in that wall cavity.

In NB, where spring snowmelt and Maritime humidity put constant pressure on older building envelopes, covering problems rather than fixing them is a risk. A wall that looks fine from the outside may have moisture-damaged insulation or early mould growth that you'd only discover by opening it up.

Practical Considerations for Your Project

Asbestos awareness is essential for any NB home built before 1980. Some older plaster formulations and the textured coatings applied over lath-and-plaster walls can contain asbestos. Before any demo, have suspect materials tested by a certified professional. Disturbing asbestos without proper abatement is a health and legal issue.

For budget context, lath-and-plaster demo typically adds $1,500-$4,000 to a room renovation depending on size, but it's almost always recovered in the value of the upgrades you can make once the walls are open. New ½-inch drywall installed on open studs runs approximately $2.50-$4.50/sq ft installed in NB, including taping, mudding, and sanding to a paint-ready finish.

Drywall installation and finishing is a job for a skilled trades person — the taping and mudding stages require real technique to achieve flat, crack-free walls. Demo of lath and plaster is something a capable homeowner can tackle with proper dust containment and PPE, but confirm there's no asbestos risk first.

If you're opening walls in an older NB home and want to connect with a contractor experienced in heritage and older housing stock, New Brunswick Renovations can connect you with local professionals for free — no obligation, just experienced local help for your project.