Question 1

How do I know if my crawlspace has a problem?

Accepted Answer

The usual signals are a musty smell on the main floor — strongest when the furnace or air handler runs — floors that feel cold or bouncy, condensation on windows, visible frost on the underside of the subfloor in winter, higher than expected heating bills, and new pest activity in the fall. In Winnipeg, cold floors over an addition are one of the most reliable indicators, because they almost always mean a crawlspace that sits outside the heated envelope.

Question 2

Do Winnipeg homes even have crawlspaces? I thought we all had basements.

Accepted Answer

Full basements are the norm here, which is exactly why crawlspaces get neglected. But there are tens of thousands of them: under rear additions, four-season sunrooms, converted porches and mudrooms in postwar bungalows; under sections of older river-lot homes that were never fully excavated; under mechanical and bonus-room areas in newer builds; and throughout rural properties on well and septic. Those spaces follow different rules from a basement and fail in different ways.

Question 3

What area do you serve?

Accepted Answer

Winnipeg and the surrounding municipalities — Headingley, East and West St. Paul, St. Andrews, Selkirk, Stonewall, Stony Mountain, Oakbank, Dugald, Beausejour, Lorette, Île-des-Chênes, St. Adolphe, Niverville, Steinbach, Landmark, La Salle and Grande Pointe, plus every Winnipeg neighbourhood. If you are just outside that list, call and ask; we will tell you plainly whether we can get there.

Question 4

Will you tell me if I do not need the work?

Accepted Answer

Yes, and it happens regularly. Plenty of crawlspaces need nothing more than longer downspout extensions, better grading away from the wall, and a moisture reading again next spring. We would rather give you that answer and earn your call when something real comes up than sell an encapsulation to a space that does not need one.

Question 5

What does encapsulation actually include?

Accepted Answer

A reinforced membrane across the soil floor and up the foundation walls, mechanically fastened and sealed at every seam and penetration; foundation vents sealed from inside; insulation moved from the floor joists to the perimeter walls; air sealing at the rim joist; and humidity control so the space holds roughly 50 to 55 percent year-round. Anything less than that is a partial measure, and we will describe it as one.

Question 6

Is encapsulation a coastal idea that does not suit Manitoba?

Accepted Answer

It suits Manitoba particularly well, for different reasons than it suits the coast. On the coast the enemy is persistent rain. Here it is a hard winter that drives indoor moisture onto cold framing and frosts the subfloor, followed by humid summers that condense moisture onto cool surfaces. Sealing, insulating at the perimeter and conditioning the space removes both failure modes and stops heating a space that is effectively outdoors.

Question 7

How much does crawlspace work cost?

Accepted Answer

It depends almost entirely on size, access and what has to happen before sealing — cleanup, old insulation removal, mould remediation, drainage, structural repair. A small sealed-and-insulated crawlspace is a very different project from a flood-damaged space needing new piers and a sump. We quote after an inspection, in writing, itemized, so you can see what each part costs and decide what to do now versus later.

Question 8

Why is my crawlspace wet only in spring?

Accepted Answer

Because spring is when the load peaks. A winter snowpack melts over a week or two onto subsoil that is still frozen and cannot absorb anything, so the water travels sideways and finds the foundation backfill — the loosest path down. It arrives at footing level under real pressure. That same crack or joint can be bone dry in August, which is why the timing of an inspection matters.

Question 9

Should my crawlspace vents be open or closed?

Accepted Answer

If the space is encapsulated, insulated at the perimeter and humidity-controlled, they should be sealed closed permanently. Open vents were the old strategy and they do not work in our climate: in summer they admit humid air that condenses on cool surfaces, and in winter they make the space nearly as cold as outdoors. Closing vents on a space that is not yet sealed or insulated, however, can make condensation worse — the sequence matters.

Question 10

There is water on the floor. Can you just seal over it?

Accepted Answer

No, and we would decline the job if that is the request. Sealing a space with an active water path traps the water inside the membrane where it is harder to see and does more damage. Liquid water needs a managed exit — grading and downspout correction outside, interior drainage and a properly discharged sump inside — before any barrier goes down.

Question 11

Why did the pipes in my crawlspace freeze?

Accepted Answer

Almost always because the space is outside the heated envelope: vented, with insulation in the floor above rather than on the perimeter walls, so the crawlspace itself runs close to outdoor temperature. Pipe insulation and heat trace treat the symptom. Insulating the perimeter, air sealing the rim joist and bringing the space into the conditioned envelope is the durable fix.

Question 12

Can crawlspace work be done in the middle of winter?

Accepted Answer

Much of it, yes. Interior work — cleanup, barrier installation, perimeter insulation, air sealing, structural support, dehumidifier installation — is unaffected by outdoor temperature. What winter does rule out is exterior excavation, grading and anything needing to reach footing depth through frozen ground. We will tell you which parts of your scope have to wait for spring.

Question 13

Why is there frost on the underside of my floor?

Accepted Answer

Warm, moist air from your living space is moving down into a crawlspace that is close to outdoor temperature, and condensing — then freezing — on the cold subfloor and rim joists. It is a clear sign the space is unconditioned and the air sealing is incomplete. When it thaws, that moisture goes into the wood, which is why frost in January often turns into mould by July.

Question 14

My sunroom floor slopes and the doors stick. Is that the crawlspace?

Accepted Answer

Very likely the support under it. The common cause in Winnipeg is piers founded above the frost line — our design frost depth runs roughly 1.8 to 2.4 metres, and shallow sonotube piers under additions sit well above that. They lift every winter and settle every spring, and after a couple of decades the addition has racked. The fix is getting support onto stable bearing below frost depth.

Question 15

Can sagging floors be made level again?

Accepted Answer

Often partially, sometimes fully, depending on how long the floor has been settled and what finishes sit above it. Correction is done gradually over days or weeks to avoid cracking drywall, plaster and tile. For a floor that has been out of level for thirty years, stabilization plus partial correction is the honest expectation — forcing it flat can cause more damage than it fixes.

Question 16

Do I need a structural engineer?

Accepted Answer

For routine post and footing replacement, usually not. For significant wall displacement, horizontal cracking that suggests lateral soil failure, changes to load paths, or anything requiring permit drawings, yes. We will tell you when we think you have crossed that line instead of quietly working around it.

Question 17

Will sealing the crawlspace keep mice out?

Accepted Answer

It helps a great deal, because sealing vents and penetrations removes the entry routes and eliminates the batt insulation they nest in. But it is not a substitute for a proper exclusion inspection, and sealing a space that currently has an active infestation traps the animals inside. Exclusion and any pest control come first, then encapsulation.

Question 18

How are mice getting in when I cannot see any openings?

Accepted Answer

An opening the diameter of a pencil is enough. The usual routes are damaged or missing vent screens, gaps where pipes and cables penetrate the wall, the seam where the rim joist meets the foundation, deteriorated mortar, gaps around sump discharge lines, and badly fitted access hatches. Our freeze-thaw cycles and clay movement open small new gaps every year, which is why exclusion is maintenance rather than a one-time job.

Question 19

Is radon really a concern in Winnipeg?

Accepted Answer

Manitoba records some of the highest indoor radon levels in Canada, and elevated results are common throughout the region. It varies house by house — your neighbour's reading does not predict yours, even in an identical home — so the only way to know is a long-term test. A crawlspace with exposed soil is the most direct entry point a house can have.

Question 20

Does sealing the crawlspace fix radon by itself?

Accepted Answer

Sealing reduces entry and sometimes brings a moderately elevated house below Health Canada's guideline of 200 becquerels per cubic metre, but it is not reliably sufficient on its own. The dependable solution is a sealed membrane plus active sub-membrane depressurization — a fan drawing continuously from beneath the barrier and venting above the roof. Test first, then retest after mitigation to confirm it worked.

Crawlspace questions, answered for this climate

General

Encapsulation

Moisture

Winter

Structural

Pests

Radon

Still unsure what you are dealing with?