Nine Insulation Myths, Debunked

1. “More insulation is always better.”

Diminishing returns are real and they bite early. Going from R–12 to R–50 is transformative. Going from R–50 to R–70 is barely measurable on a bill and the rebate will not pay for it. Past about R–50 in an Ontario attic, your money is better spent on air sealing, ventilation or the rim joist.

2. “Insulation stops draughts.”

Most insulation is not an air barrier. Air moves straight through fibreglass. Stopping draughts is a sealing job — caulk, foam, gaskets at the penetrations — which is why we seal before we blow.

3. “Attic insulation is only about winter.”

An uninsulated Ontario attic reaches 55 to 65 °C on a July afternoon, sitting directly on your bedroom ceiling. More on the summer side here.

4. “My house is too old to insulate.”

Old houses are usually the best candidates, because they start from nothing. What is true is that they need care: knob-and-tube wiring has to be dealt with first, and solid masonry walls have no cavity to fill. More on century houses here.

5. “Spray foam is the best insulation.”

It is the best in specific places — rim joists, crawlspaces, cathedral ceilings, awkward geometry. Across an open attic floor it costs several times what blown cellulose costs to reach the same R-value. Where it earns its price.

6. “Vents let the heat out, so seal them up.”

This one causes real damage. Attic vents are there to carry moisture out. Block them and the attic frosts, then rots. The insulation goes on the attic floor; the ventilation happens above it.

7. “Old insulation has to come out.”

This is the one that costs us money. If your existing material is dry, clean and undisturbed, we blow straight over it and the depths add up. Removal is genuinely necessary when material is wet, contaminated or compacted flat — and it is oversold constantly.

8. “The rebate makes it free.”

And this is the other one. The attic rebate is capped at 50% of the invoice after tax. By design, you always pay at least half. The full arithmetic.

9. “It is your last chance, the programme ends on 30 November.”

Ask where that date is published, because it is not. We read both programme publishers on 24 September 2026 and neither states an end date, a closing date or a deadline. This site carried that countdown itself until we went looking for the source, found none, and took it down.

What is verifiable today is that the programme has closed registrations for new contractors on the attic stream — “Contractor registrations for the attic program stream are currently closed; no new applications are being accepted.” — which is a real constraint on who can file your claim, and one you can check yourself in a click.