Ventilation and Insulation Options

Insulation and ventilation is pretty much taken for granted in the home. But what about those garden buildings you intend to use throughout the year? Without heating, insulation or ventilation, they can be out of bounds at certain times of the year.

But if you want to maintain a pleasant, ambient temperature in your garden building throughout the year, then it’s a good idea to install some type of ventilation and insulation system designed specifically for that space. This will help to create a condensation-free environment that keeps warm throughout the winter, and cool in the hot summer months.

Insulation in particular will also help you to keep those otherwise expensive home energy bills down. Consider that insulation your home can save you up to 60% on your energy bills – now transfer this to the cost of running an expensive heater in your garden building and you’ll begin to understand just how cost effective good energy conservation insulation can be. Likewise, Air Conditioning units in the summer will greedily consume energy, so some forethought will keep you cool and your energy bills even cooler.

Where Do I Need to Ventilate?

In summer, simply opening a door or window or skylight could count as effective insulation. But in the winter months, opening a window can leave you feeling just that bit too fresh and cool! So what other ventilation options are available to avoid condensation?

In brick buildings, you could make sure that you install an air brick into an external wall. This should be sited either high up, or below flooring level, around 6 inches above ground below the level of any damp course.

There is also, of course, the option of using a wall-mounted electronic air conditioning unit. However, these prove expensive to buy, expensive to install and expensive to run. You could always opt for a wall-mounted extractor fan – these are usually available as centrifugal (tangential) fans or propeller-like axial flow fans, which can also be installed in windows. These types of extractor fans are operated electronically via a pull-chord or wall switch and have low energy consumption. However, the downside is that they can be a bit noisy and fairly complex to install, so will probably need a qualified electrician.

However you should still consider condensation. Condensation can build up underneath floorboards in lofts, on windows and in walls. Condensation occurs when warm air meets cooler air, so it usually occurs at higher levels in a room or loft. So if your garden building has a loft space and you intend to insulate it, you should also consider that the loft flooring insulation may trap condensation in the loft roof insulation. However, by installing foil-faced plasterboard or polythene backed rolls of fibreglass insulation, you can address the problem of ventilation and insulation at the same time.

Where Do I Need to Insulate?

The first thing to consider is where in your garden building you will need to insulate. This is important from both an energy conservation and budgetary point of view. In all buildings, the most heat is lost through the roof, followed by exterior non-insulated walls. A smaller but significant amount of heat is also lost through doors, windows and through the flooring.

In timber-framed construction designs, draughty gaps in timbers on walls, around the door and on the floor will contribute to a lot of heat loss. But it’s worth considering that inadequate insulation can lead to condensation, rendering the insulation ineffective. Thus, it’s important to have both good insulation and good ventilation in your garden building.

Insulation Options

If your garden construction has not yet been built, it is a good time to consider your insulation materials, as your choices may be less limited than retro-fitting insulation. There are many options for insulation, the most common being:

Blanket rolls of fibreglass insulation – the cheapest option that can be fitted between joists, but difficult to compress as it gets older. This type of fibreglass insulation is ineffective if it comes into contact with condensation, which is why investing in foil-backed fibreglass blankets is a good idea. The foil or polythene backing acts as a vapour barrier, maintaining the reliability of the insulation.

Expanded polystyrene sheets are great design for retro-fitting, as they can easily be slid into place behind boards. These polystyrene sheets are, however, a more expensive option so may only be suitable for insulating difficult areas. You can purchase fire retardant sheets for domestic use, labelled FRA or Type A.

Reflective foil (aka building paper) is supplied in rolls and is another great option for easy retro fitting. It is most commonly laid over joists or pinned to rafters. Like the foil-backed fibreglass insulation, it acts as a vapour barrier and bounces heat off the reflective surface into the coldest spaces.

To make sure that you buy enough material, always measure the insulation space beforehand. You may need more or less material depending on the material you opt for and the type of garden construction (e.g. timber framed or brick) you are insulating. It’s best to consult a building merchant, as they will be able to advise and help you to calculate your costs per square metre.