A Guide To Insulating Your Bathroom

Insulating Bathroom

When it comes to insulating bathrooms, they undergo the most extreme changes in temperature because of how we use them, but making sure your bathroom insulation is in check is important. Without proper bathroom insulation materials, your bathroom could be costing you £100s in energy bills.

Due to the shifts in humidity and temperature when a bath or shower is running, strong air flow is often required in order to keep your bathroom from getting damp and suffering from mould issues. However, this presents an issue. Constant airflow mixed with little or no insulation can mean your bathroom is a sieve for heat in your home.

By investing some time and money in better insulation you can keep your bathroom warm and ensure the rest of your house benefits too. Bathroom wall insulation could save you £100s each year on your energy bills, so why wouldn’t you consider insulating bathroom walls in your home today?

Improving Your Bathroom’s Insulation


1. Replace the silicone sealant around the window frames

The sealant surrounding window borders can deteriorate over time, allowing heat to escape and cold air to enter the bathroom. Using silicone sealant to reseal window edges is not only easy, but is also one of the cheapest options available to you. This is an important first step before you attempt to install insulation.

Applying Sealant to Windows in Bathroom

2. Install Weather Stripping to the Edges of Windows and Doors

A more durable alternative to simply replacing silicone sealant around your windows, weather stripping can be found at most DIY stores. It is supplied in a large coil or roll of rubber and plastic sealant that can be cut to fit any door or window.

The procedure of sealing the edges in this manner is similar to replacing the sealant as we mentioned above, but it is more effective in preventing cold air and water ingress through any window gaps.

3. Insulation film for windows

A great first step from an insulation perspective, you can install a thin plastic film on your bathroom windows. This is better known as window insulation film, and it is designed to significantly minimise heat loss.

The film is typically applied directly to a window using heat, such as a hairdryer, to shrink the film around the glass, or even the window ledge. Window insulation film can also help to restrict or prevent condensation, reducing the risk of mould and mildew.

4. Install Adequate Ventilation

Opening windows is a fast and effective way to ventilate your bathroom, but heat can be lost extremely quickly and is typically slow to reheat, especially during the colder months.

Installing an extractor fan in your bathroom however will help to keep your bathroom ventilated and keep condensation and mould at bay, as well as eliminating the need for you to keep opening and closing your bathroom window.

5. Install Foam Pipe Insulation

Proper insulation around pipes limits heat transfer and can help lower your overall energy consumption through more efficient heating. It also acts as a vapour barrier against moisture which improves overall thermal efficiency and saves you money.

Foam pipe insulation is very cheap, and aside from bringing you bill savings, can also help avoid costly plumbing issues with pipes freezing, and later bursting, when the temperatures fall significantly.

6. Install Wall Insulation

Bathroom walls are notoriously cold because of the cavity behind them that contains the pipework for your bath, shower, sink and toilet. One way to ensure your bathroom stays as warm as possible is to install wall insulation. Insulated walls will dramatically improve your cold bathroom and make it more thermally efficient.

There are numerous types of insulation materials that would be suitable for insulating your bathroom walls and it is all down to personal choice, budget and whether you possess any DIY skills yourself.

Spray Foam, Mineral Glass Insulation, Rigid Foam Insulation Panels and Rigid Board Insulation, such as Celotex, are just a few types of insulation material that would be perfect for insulating bathrooms, or, if you wanted to keep things as environmentally sound as possible, Sheep’s Wool Insulation is another viable option.

Whichever insulation material you decide on, the installation method is practically the same. First, you would need to build a wooden framework or timber frame to attach to your bathroom walls. Once this is in place you can either spray the foam insulation straight onto the walls within the framework or install the rigid board insulation, sheep’s wool insulation or mineral glass insulation, as per the manufacturer’s instructions.

Once the insulation is in place you will need to attach plasterboard to the frame to keep the insulation in place, and then have your bathroom walls plastered, ready for decoration.

If your property is a solid wall construction, and therefore without cavities, then insulating your exterior walls may be an option, but can be a somewhat costly option. Likewise, having the floor insulated is also a potential option and can make your bathroom feel even more comfortable when combined with underfloor heating (providing the insulation is compatible with heating).

7. Using Foam In The Bathroom

Whether it’s spray foam or foam pipe insulation, or even expanding foam sheets installed beneath the bathtub to keep the bathroom warm, there is one thing you’ll need to think about carefully: moisture.

Foam in all its many varieties was not made to absorb moisture, and it can actually compromise the insulation’s properties if it is exposed to water for too long. In a bathroom, this could potentially cause issues.

Of course, if the insulation is in your bathroom walls, then there’s no reason why it should get wet, but if there’s a problem with any pipework or any unfortunate leaks, then you could be in a situation where your insulation is no longer effective because it’s too damp.

Before installing foam insulation materials in your bathroom, seriously consider if your bathroom may need some additional work first to ensure your new insulation material can last for as long as possible.

Reasons To Install Bathroom Insulation

There are plenty of reasons why installing bathroom insulation just makes sense, such as:

Keeps Your Bathroom Warm

Stable temperatures are important in every room of your house, but adding insulation to keep your bathroom warmer also means you’ll prevent hot, wet air from your shower or bath from escaping into the rest of your house and also keep your bathroom at a stable temperature during colder months when pipes freezing and potentially bursting could become a real issue.

Protects Bathroom Walls From Mould

Moisture control is another huge benefit of insulation, and when bathroom walls are properly insulated, the humid air from the bathroom won’t hit your cold bathroom walls and create condensation. This condensation is the typical culprit for mould and mildew issues, so by preventing it, you’ll stop the primary cause of mould issues in your bathroom.

Saves You Money

Energy waste is the biggest concern with uninsulated bathrooms, as they can be responsible for the loss of much of your home’s heat. By insulating your bathroom, you’ll reduce energy waste and therefore energy costs, saving you money.

Makes Your Home Greener

This links back to energy waste again, but if your bathroom is losing heat quickly, you’ll be keeping your heating on for longer and therefore emitting more carbon into the atmosphere than is necessary. By having insulation added, you can make your home greener and therefore reduce your carbon footprint.

Bathroom Insulation Summary

Insulating your bathroom is often a fairly easy job if you have some competent DIY skills, but we would always recommend contacting the professionals if you’re unsure about the work. By applying insulation to interior walls, and using some of the other insulation methods outlined above to reduce heat loss, you can make your home more energy efficient and bring long-term savings. It will also help with better moisture control in your bathroom.

Even if you are limited in budget, there are plenty of easy draught excluding measures you can implement that can make all the difference to your energy bills. If you can stretch to cover the cost of having insulation installed by a professional, whether spray foam or some other option, to insulate your bathroom properly, you will very quickly find the initial cost will be covered by the energy savings you are making over time.

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