Every stone house owner wants to insulate it themselves. In this article, you’ll learn about different insulation materials, why insulation is necessary, and how to choose the right material.
Why insulate a stone house from the outside
There are several reasons to insulate a stone house externally.
The main characteristic of a stone house is its high thermal conductivity. That’s why insulation is used to maintain warmth inside the house.
As utility prices continue to rise, insulation helps retain generated heat, reducing your heating bills.
Another reason is to prevent mold formation. Mold often appears due to the temperature difference between indoor and outdoor environments.
Additionally, exterior insulation extends the building’s lifespan (by protecting it from environmental factors) and offers opportunities for decorative wall finishes.
Mineral wool: pros, cons, and installation guide
What is mineral wool? It’s a fibrous material made from melted rocks, metallurgical slag, or their mixtures. It’s widely used for insulation thanks to a range of benefits. Here are the main advantages of mineral wool for stone houses:
- Low thermal conductivity
- High fire resistance – withstands temperatures over 400°C
- Resistant to temperature extremes without deformation
- Chemically and biologically resistant
- High vapor permeability – supports indoor air circulation
- Easy installation process
Disadvantages:
- Heavy weight
- Requires water-repellent treatment to reduce moisture absorption
Installation steps:
To insulate your house with mineral wool, prepare the following: spatulas, floats, rollers (medium nap), mixing buckets, plastic trowels, a construction mixer, a perforator, and a level.
- Start by gluing the wool to the façade using facade adhesive, beginning from the bottom row and working upward.
- After 24 hours (once the glue dries), inspect the surface. Remove protruding edges using a float.
- Fill joints over 2 mm wide with mineral wool.
- Secure each board with at least 5 dowels.
- Apply a leveling adhesive layer from bottom to top, embed fiberglass mesh, and cover with facade adhesive.
- Finish with decorative plaster.
EPS foam: installation steps, pros and cons
Polystyrene is commonly used for insulating stone buildings because it doesn’t absorb moisture, has excellent thermal properties, keeps its shape over time, is lightweight, affordable, and easy to install. It’s also odorless and non-toxic.
Pros:
- Great heat insulation
- Water-resistant
- Affordable and lightweight
- Easy to work with
Cons:
- Can attract rodents
- Deteriorates under UV exposure
- Flammable
- Suitable only for flat, solid walls
Installation process:
- Thoroughly clean the walls.
- Attach a starter track along the wall base.
- Apply adhesive to the polystyrene foam and press it firmly against the wall. The boards should be placed as tightly as possible, and all gaps should be filled with expanding foam.
- Secure each board with plastic dowels.
- Create a reinforced layer using mesh to prevent cracks.
- Install perforated corner beads.
- Apply the final reinforcing layer.
If you lack experience, consider hiring professionals for a quality result.
EPS foam: everything you need to know
This insulation material has several notable advantages:
- Excellent thermal insulation, especially important in winter
- Long service life—over 60 years
- Strong soundproofing—absorbs up to 40 dB
- Low flammability—it chars rather than burns
- Can be applied to any surface
- Provides airtight, seamless coverage
Disadvantages:
- Sensitive to UV rays
- Higher cost
Which insulation should you choose?
We reviewed three popular options: polystyrene, mineral wool, and EPS foam. All offer excellent thermal and sound insulation, and resist temperature changes.
When choosing insulation, consider the following:
- thermal conductivity
- porosity
- weight
- density
- vapor permeability
- durability
- cost
- flexibility and resilience
- resistance to mold, pests, and insects
- resistance to heat and UV
- sound insulation
- eco-friendliness
- acidity
- flammability
- waterproofing
- water absorption
- strength under bending, tension, and compression
Only by evaluating these factors can you choose the most suitable insulation material for your stone house.