Keeping old houses comfortably warm and energy efficient is tough. Older homes weren’t usually fitted with insulation. When they were, the materials often settled, lost their insulating value, and sometimes deteriorated. Today, home insulation options are abundant, with a myriad of products that are both cost-effective and energy saving – the big decision is what to do and how to do it.
The first step in insulating an old house is to determine the status of the home’s insulation. And while a cursory homeowner assessment might be adequate, it’s best to have a professional assess the entire house – from attic to basement to exterior walls. An expert can accurately evaluate the overall status: the scope of insulation, the extent of air leakage, and the options for re-insulation.
One of the biggest problems in an old house is air leakage. In winter, heated inside air leaks out, and in summer, warm outdoor air creeps in. Old chimneys and fireplaces are a definite source of air leakage, while aging doors and windows also contribute. But most important is to address the top of the house – the attic and roof cavity, which is where most indoor heat rises and escapes.
Depending on the age of the house, there may well be dangerous and even hazardous insulation products installed. This is another reason why a professional assessment is preferred, especially if asbestos or urea formaldehyde are suspected. Inasmuch as these materials might have been acceptable at the time, today they must be remediated, with full restoration work recommended.
For many insulation contractors, the preference when insulating or re-insulating an old house is to begin in the attic – a place with the best return on investment. For the professionals, insulation is only the start. It’s also important to ensure effective ventilation and moisture control. It’s about creating a complete “system” that incorporates air sealing, thermal insulation, and ventilation.
Choosing the right type of insulation product for an older house is also a critical decision. Today, many insulation professionals are installing spray foam insulation – it’s the most multi-purpose application available. When professionally installed, specifically in the attic and roof, spray foam will block airflow, control moisture, and insulate at a very high R-Value – all in one application.
When installed throughout an attic, spray foam covers the space with a thick, dense “envelope”. Everything is completely covered – the attic support beams; the electrical wiring; the heating and return ducts; and all of the cracks and crevices that surround. With spray foam, the finished space is fully airtight, moisture-proof, and insulated with a very high R-Value rating per installed inch.
In older homes, the spray foam approach will deliver more benefits than other options, whether it’s in the attic, the walls, the basement, or the floors. It is, however, a premium product, and may not suit all budgets. This is where a “hybrid” alternative might be a viable appropriate. It’s a way of combining spray foam with a secondary insulation product to ensure cost-effectiveness.