What Are The Different Kinds of Insulation?

Posted by Turkstra

Choosing the right insulation for your Ontario home is one of the most impactful decisions you can make, for comfort, energy costs, and long-term durability. The challenge is that there are several types on the market, each with its own strengths, limitations, and ideal applications. Here's what you need to know.

Batt Insulation: Fibreglass & Mineral Wool

Batt insulation is what most people picture when they think of insulation (those pink or yellow blanket-like rolls that fit between wall studs and floor joists). Made from either fibreglass or mineral wool (rock wool), it's the most widely used insulation type in Canadian residential construction.

Best For

• Exterior walls, interior walls, and attic floors
• Standard stud spacing (16" or 24" on centre)
• DIY-friendly projects — no special tools required
• Budget-conscious builds

R-Value

Approximately R-3.0 to R-4.0 per inch, depending on the product.

Rigid Foam Insulation: XPS, EPS & Polyiso Explained

Rigid foam insulation comes in solid boards and is typically used on the exterior of walls, under concrete slabs, and in areas where moisture is a concern. There are three main types you'll encounter on an Ontario project:

• EPS (Expanded Polystyrene) — the white beadboard foam; affordable and versatile
• XPS (Extruded Polystyrene) — blue or pink boards; higher moisture resistance, ideal for below-grade
• Polyiso (Polyisocyanurate) — highest R-value per inch; used heavily in commercial builds and roof assemblies

Best For

• Foundation walls and below-grade applications
• Continuous insulation on exterior sheathing
• Basement floors and crawlspaces
• Anywhere you need a vapour retarder built in

R-Value

R-3.8 (EPS) to R-6.5 (Polyiso) per inch.

Ontario Tip

XPS is the go-to for below-grade applications in Ontario because it retains its R-value even when damp. If you're insulating a basement, don't use fibreglass batts against the foundation wall. Use rigid foam first, then batt over top if additional R-value is needed.

Spray Foam Insulation: Open-Cell vs. Closed-Cell

Spray polyurethane foam (SPF) is applied as a liquid that expands and hardens, filling every gap, crack, and irregular surface. It provides both insulation and an air barrier in one product whish is a major advantage for energy performance that neither batt nor rigid foam can match on its own.

There are two types:

• Open-cell foam — lower density, more flexible, lower R-value (~R-3.7/inch); great for interior walls and sound control
• Closed-cell foam — dense, rigid, very high R-value (~R-6.5–7/inch); acts as a vapour barrier; best for rooflines and exposed applications

Best For

• Attic rooflines and cathedral ceilings
• Rim joists and hard-to-reach gaps
• Older homes with air leakage problems
• High-performance and Net Zero builds

R-Value

R-3.7 (open-cell) to R-7.0 (closed-cell) per inch.

Ontario Tip

Closed-cell spray foam on a rim joist is one of the most cost-effective upgrades an Ontario homeowner can make. It seals out cold air, moisture, and pests in one step. Many energy auditors consider it the single best bang-for-buck insulation upgrade in older homes.

Quick Comparison: Which Insulation Type Is Right for Your Project?

Every insulation type has its place and the right choice depends on where you're insulating, your budget, and your performance targets. Here's a side-by-side summary:

Frequently Asked Questions

What is the minimum insulation R-value required in Ontario exterior walls?

Ontario Building Code requires a minimum of R-22 in exterior walls for most climate zones. If you're using standard 2×6 framing (5.5" cavity), a high-density fibreglass or mineral wool batt gets you close — but many builders add a layer of continuous rigid foam on the exterior to meet or exceed code and reduce thermal bridging through the studs.

What is the best insulation for a basement in Ontario?

XPS rigid foam against the foundation wall, followed by mineral wool batt in a framed interior wall if additional R-value is needed. Never install fibreglass batts directly against a concrete foundation wall — moisture migrating through the concrete will saturate the batt, reducing its R-value and potentially creating mould conditions.

What is the best bang-for-buck insulation upgrade in an older Ontario home?

Closed-cell spray foam on rim joists, without question. Rim joists are one of the largest sources of heat loss and air infiltration in older homes, and spray foam seals and insulates in one step. Most energy auditors rank this as the highest return-on-investment insulation upgrade available. It's also a relatively small area, so the cost is manageable even with professional installation.

What is the difference between open-cell and closed-cell spray foam?

Open-cell foam expands significantly, is softer and more flexible, and achieves around R-3.7 per inch. It's good for filling wall cavities and providing sound attenuation but does not act as a vapour barrier. Closed-cell foam is denser, expands less, achieves R-6.5 to R-7 per inch, and functions as both an air barrier and a vapour barrier — making it the right choice for rooflines, rim joists, and any application where moisture control matters.

Can I install batt insulation myself?

Yes! Batt insulation is the most DIY-accessible insulation type. It requires no special tools or equipment beyond a utility knife, straight edge, and appropriate PPE (gloves, safety glasses, and a dust mask for fiberglass). The key to effective DIY batt installation is cutting accurately to fill the cavity completely without compressing the batt, which reduces its R-value. Mineral wool is easier to handle and cut cleanly than fibreglass.

Ready to Get Started?

Whether you're building new or upgrading an existing home, the team at Turkstra can help you choose the right insulation product for your project and Ontario's climate. We carry a full range of insulation products and love helping homeowners and contractors make the right call for their project. Contact us today!