Housewrap is your home’s last defense against the damaging effects of rot. They are constructed to be water and UV resistant, as well as handle years of abuse in different climates. If a home is constructed without properly installing housewrap and siding , the insulated framing cavities can get wet and can lead to rapid rot and decay. When installed properly, housewraps will keep the water out, and keep the structure of your home dry.
What is Housewrap?
Housewrap is a water-resistant synthetic material that protects the structure of your home from moisture damage. Not only does it protect your home against ice and water intrusion, it also creates a drainage plane, allowing water to evaporate before seeping into your home’s structure. This material usually contains polymers, nylon, or fiberglass and comes in large rolls for easy application. By acting as an insulator and reducing the exchange of airflow, housewrap can also save you money in energy bills.
Is Tar Paper a Good Housewrap Alternative?
Tar paper is a heavy-duty material typically used in roofing applications. Some contractors also install it over sheathing for extra water protection. It is bulkier, and more difficult to work with, but you can find contractors who swear by it since it doesn’t rip as easily. Tar paper is said to withstand extreme hot or cold climates and high winds better than standard housewrap. It all depends on your local climate. One potential drawback of using tar paper is the potential corrosive reaction it can have to wood siding options. For instance, you can find people talking about how, when cedar siding gets wet, it can leach resins onto the material, thereby causing a faster breakdown of the tar paper. Regardless of the siding option you choose, this just once again proves that proper installation of siding is critical.
HOUSEWRAP INSTALLATION TIPS
Rule of Thumb #1: Horizontally Overlap
Start at the bottom of the sheathing and horizontally overlap the housewrap (or tar paper). Allow each sheet to overlap around four to six inches. Any areas that may be vulnerable to more moisture can benefit from extra layers of wrap.
Rule of Thumb #2: Don’t Neglect the Attic
Many builders assume housewrap can act only as a barrier for airflow and not a barrier for weather. This is a terrible thing to assume. The attic walls are the most exposed area of your home and if they aren’t wrapped properly this can lead to rain getting behind the siding and can intrude into the space behind the housewrap. The result? Rapid rot and decay.
Rule of Thumb #3: The Corners Need Protection, Too
Another vulnerable, and often neglected spot prone to water and wind intrusion are the corners of the home. While wrapping outside corners is pretty standard, inside covering inside corners can be tricky. One great tip is to fold a layer of housewrap into the inside corner. Then take piece of scrap wood (i.e., 2×4), press it tight into the corner, pull it taught for a tight fit, and then tack it with a staple gun. This will ensure that you have a nice clean joint when installing rainscreen siding.
Rule of Thumb #4: Flashings Help Keep Water Out
Install flashing around the heads of windows and doors to keep water out of the casings. Caulk may seem like a good idea, but it’s just not reliable. Water will eventually find its way into the casing. For a long term, headache (and repair bill) free solution install the flashing.
Rule of Thumb #5: Layer Roof Flashing Properly
One common oversight is when the roof flashing doesn’t get layered properly. The flashing should be tucked up underneath the housewrap to prevent water intrusion. Improper installation can result in a roof leak. The paper needs to be held up until the flashing is placed over top. Or you can cut into the housewrap. If you do cut the housewrap, place a piece of tar paper on top of the housewrap to prevent water intrusion. Basically, the structure will benefit with extra layers of housewrap anywhere the roof has intersecting points.
If you are considering installing wood siding, take a look at the underlying structure and state of your home. It’s easier to re-wrap your house, fix tears, or re-flash the windows or doors now instead of waiting until there is a larger problem at hand. You don’t just want your home to look beautiful, you want it to last too.