How do you insulate walls in an old house?

Author: Antonietta Denesik  |  Last update: Sunday, September 21, 2025

How to Insulate Walls in an Old House
  1. Apply a house wrap/vapor barrier to exterior walls.
  2. Attach 1-inch foam board insulation.
  3. Install siding over the insulation.
  4. Replace old windows with energy-efficient units.
  5. Caulk window trim and use weatherstripping to reduce air leaks.

What is the best insulation for walls in an old house?

Insulating Open Walls During Renovation

Spray foam: Open-cell or closed-cell spray foam can provide excellent insulation and air sealing in one application. Combination approach: Use spray foam to seal air leaks and fill odd-shaped cavities, then supplement with batt insulation for cost-effectiveness.

Can you insulate the walls of an existing house?

Unless your home was specially constructed for energy efficiency, you can probably reduce your energy bills by adding more insulation. Many older homes have less insulation than homes built today, but even adding insulation to a newer home can pay for itself within a few years.

What is the cheapest way to insulate internal walls?

Thermal lining paper is among the cheapest ways to insulate internal walls. This thick, insulating wallpaper can be easily applied directly to walls, making it a quick and straightforward solution. Costing around £10 per square metre, it effectively reduces heat loss and is perfect for smaller DIY projects.

How much does it cost to insulate walls in an old house?

Wall Insulation Cost Factors

Insulating walls can cost between $1 and $4 per square foot, with overall costs varying based on the wall area of your home. Mineral wool and fiberglass batts – both of which are common for wall insulation – are priced at $1 to $1.50 per square foot.

How to Choose and Use Insulation | This Old House

How do you insulate an old house without tearing down walls?

How to Insulate Walls in an Old House
  1. Apply a house wrap/vapor barrier to exterior walls.
  2. Attach 1-inch foam board insulation.
  3. Install siding over the insulation.
  4. Replace old windows with energy-efficient units.
  5. Caulk window trim and use weatherstripping to reduce air leaks.

What is the cheapest way to insulate a wall?

Here are the three cheapest ways to insulate internal walls:
  1. Insulation Boards. Insulation boards are a popular choice for internal wall insulation because they are relatively affordable and easy to install. ...
  2. Battening the Walls. ...
  3. Building a Stud Wall.

What is the best wall covering for cold walls?

Wallrock Thermal Liner is a thicker alternative to standard wallpaper, making it a popular option for those aiming to address issues with cold walls and ceilings while also reducing noise pollution.

How do you insulate an existing wall from the inside?

Internal wall insulation is done by fitting rigid insulation boards to the wall, or by building a stud wall filled in with insulation material such as mineral wool fibre. Internal insulation: Is generally cheaper to install than external wall insulation.

Can you put too much insulation in walls?

It is possible to over-insulate your house so much that it can't breathe. The whole point of home insulation is to tightly seal your home's interior. But if it becomes too tightly sealed with too many layers of insulation, moisture can get trapped inside those layers.

How to tell if your house needs more insulation?

How to tell if your house is poorly insulated
  1. Energy bills are higher in the winter. ...
  2. Constant fluctuations in temperature. ...
  3. Frozen pipes in freezing temperatures. ...
  4. Condensation within your household. ...
  5. Pests hide in your walls and attic. ...
  6. Ice dams on the roof. ...
  7. Drafts are present. ...
  8. Water drips from the attic.

How to insulate a cold wall from the inside without?

Here are several methods you can use to insulate a cold wall from the inside:
  1. Insulated Plasterboard. ...
  2. Timber Frame Construction. ...
  3. Insulated Wallpaper. ...
  4. Polystyrene Insulation.

What happens if your walls are not insulated?

Uninsulated external walls can also cause structural damage to your home over time. When water penetrates the walls, it can freeze and expand, causing cracks and weakening the structure of the wall. This can lead to more significant problems, such as collapsing walls, which can be dangerous.

Why do old houses have spaces between the walls?

The most important benefit of timber-framed housing is exactly this space in between. Plumbing systems, electrical and telephone wires can easily be hidden in the gap between the plasterboards and thus avoid inelegant results considering the living space.

Can you blown in insulation in existing walls?

Both injection foam and blown-in cellulose can be installed in existing walls similarly. First, a row of siding is removed, and a hole is drilled into each stud cavity. The insulation material is then injected or blown in until the cavity is full. Afterwards, the hole is plugged, and the siding is replaced.

How do you stop cold coming through walls?

The easiest way to make your walls warmer is by adding extra insulation. The cost of this will depend on your property and the size of the problem. If you live in an old solid-walled property, then you may need to invest in a large insulation project like installing an external insulation system.

What can I put on my walls to make it warmer?

Let's liven up the whole room by hanging a stunning tapestry on the wall. If you hang it on an outer wall you'll gain instant insulation—even a nice blanket or secondhand rug can add pizzazz and warmth to your living space. You can further insulate a room by strategically placing a bookcase along an outside wall.

How to insulate an exterior wall from the inside?

Inside Exterior Walls

You can also stuff small batts around areas like plumbing, vents, windows and doors. Once your batting is up, install a continuous sheet of vapour barrier across the wall ensuring complete coverage. Make sure to seal joints and overlap them when possible.

How to insulate an old house cheaply?

5 DIY Ways to Insulate Your Home on the Cheap
  1. Cover any air leaks with weatherproofing. Use weatherproofing strips and caulking to seal any air leaks in your doors and windows. ...
  2. Add thick curtains to your windows. ...
  3. Fix drafty doors with a door snake. ...
  4. Plug your chimney when not in use. ...
  5. Seal your attic air leaks.

Is there a way to insulate walls without removing drywall?

The best, and most common, method for adding insulation without removing drywall is through the drill-and-fill method. Using the drill-and-fill method, the insulation is blown directly into a closed wall through small holes drilled into the wall.

How much does it cost to insulate a house wall?

Fiberglass Batts or Rolls: $0.40 to $1.20 per square foot. Cellulose Insulation: $0.50 to $1.50 per square foot. Spray Foam Insulation: $1.50 to $3.50 per square foot. Rigid Foam Board Insulation: $0.75 to $2.50 per square foot.

Does Lowes install insulation?

Lowe's is here to help with our blown-in and batt insulation installation service. There are two types of insulation material to choose from, and which one you choose is up to you. Cellulose insulation, made from recycled paper and treated to be fire-resistant, is the most common material used.

How many bags of insulation do I need for 1000 square feet?

For example, if the square footage of the room you're planning on insulating is 1,000 square feet and you want to achieve an R-value of 60, you will need approximately 17 bags to fully insulate your room. If you are using loose fill insulation, the coverage varies based on the R value that is needed.

Can I install insulation myself?

DIY Home Insulation Pros

Fiberglass batts and rolls are fairly inexpensive and can be installed in open and accessible areas like attics, crawl spaces, and rim joists by the handyman homeowner. The homeowner can install blown-in cellulose insulation, but a machine must be rented for the installation.

Previous article
Do hard-wired smoke detectors ever need to be replaced?
Next article
Can you stop blossom end rot once it starts?