All posts by : Heidi Shaw

Everybody has seen Tyvek house wrap on the sides of homes and commercial buildings during construction. What’s it for? Well, Tyvek blocks air movement and sheds water but allows moisture to travel through it. Houses build up quite a bit of moisture from cooking, breathing, washing, and bathing. And houses need to “breathe” (which means moisture needs to be able to exit the building so that it doesn’t cause wood rot or mold inside the walls.) It comes in rolls and gets applied to the outside of the structure between the plywood sheathing and the siding.

Tyvek is made of olefin, (which is very lite) and was patented by DuPont in 1956. Its use has been growing ever since. It’s very functional and easy to install.

So now, when you drive by new construction and see Tyvek house wrap, you’ll know what it’s all about!

When it comes to saving money associated with heating and cooling, air movement, between the outside and inside the structure is the source of most energy loss. Stopping air movement is critical and is the “low hanging fruit on the energy savings tree”.

Most homes we inspect use fiberglass or cellulose insulation bats on the floor of the attic. This type of construction requires attic venting which provides a free flow of air from the attic to the outside. Making matters worse, bat insulation is not good at stopping air flow at penetrations in the attic floor where electrical, plumbing and HVAC lines are going through the attic floor to the living space below. So there’s a flow of conditioned air from the living space, through the attic, and then to the exterior of the home through the attic venting system. Therefore, there is a substantial heating/cooling loss from inside your home through the attic and to the exterior of the home. And obviously, we all pay dearly for energy to keep the house warm or cool depending on the season.

These days, many homes utilize spray foam as an insulation material which is typically applied directly to the underside of the roof and doesn’t require attic vents. All the nooks and crannies are sealed with the spray foam and as result, air movement, from inside the home to the outside is pretty much stopped, providing a substantial savings.

Some people have inquired about the impact of spray foam insulation and the possibility of indoor air quality issues due to a lack of fresh air. It’s an excellent question!

Spray foam insulation provides such a good “air block” that if the entire house is insulated with spray foam it could cause a problem with indoor air quality (IAQ), and mechanical ventilation may be needed due to a lack of fresh air. There are lots of different systems that can introduce fresh air, some of them are energy efficient. Energy recovery ventilator (ERV) systems provide a controllable amount of fresh air in the structure and are energy efficient. In an older house there is probably enough air leakage through the walls, windows, doors, and other openings that more than likely there’s enough natural ventilation in the structure without adding a mechanical ventilation system even if the attic is insulated with spray foam.

So, in our opinion, spray foam insulation applied to the underside of the roof is the best way to go with insulation. And by the way, while you’re at it, it pays to seal any air gaps in the basement perimeter walls especially at the top of the foundation where it meets the wood framing. If you decide to explore the installation of spray foam, keep indoor air quality in mind. A good AC contractor or spray foam installer should be able to help guide you with this concern.

If you are interested, all our previous newsletters are available on our website blog. Click on the following link and it will take you right to it.

https://safeharborinspections.com/blog/“

Proper operation of your air conditioning unit requires a clean air filter. If the air filter gets clogged, it can cause the air conditioning unit to freeze up and stop working or at least degrade its functionality.

We’re not at the end of the cooling season yet. People often forget to change the filter this time of year. But it’s easy and it’s cheap, and it’s a good idea to change it every 3 months. By the way, there are good filters and there are cheap filters. We recommend a HEPA (High-Efficiency Particulate Absorbing filter). HEPA filters are substantially better than the cheap ones. If you want to go to the next level, talk to your air conditioning service company about electrostatic filtration which utilizes electricity and HEPA filters to remove about 99% of particulates including many strains of mold, bacteria, and viruses. By the way, all these suggestions apply to hot air heating systems. In the winter, the air in your home is often very dry which leads to more particulates in the air which makes it even more important to have a good filtration system.

If you are interested, all our previous newsletters are available on our website blog. Click on the following link and it will take you right to it.

https://safeharborinspections.com/blog/