Energy Efficient Rehab AdvisorHomeAboutHUD Logo

Caulking and Weatherstripping

Caulking and weatherstripping may be the easiest form of sealing leaks for homeowners and tenants. Not only does caulking and weatherstripping prevent air from entering or escaping the home, it also prevents the spread of moisture, particularly around pipes, drains, and faucets.

Getting Started

Conduct a visual inspection to locate caulk that is cracked or deteriorated and weatherstripping that has gaps in the seal. You may also be able to tell if a window or door need better weather stripping by trying to rattle the door or window, or by looking around the edges to see if any light penetrates through the cracks.

Selection and Application of Caulk

Caulk comes in cartridges that will be inserted into half barrel caulking guns. For small caulking jobs, you can find it in small squeeze tubes or ropes. Expect to use about a half-cartridge per window or door and four cartridges for the foundation sill, and at least one more for around faucets, vents, pipes, and electrical outlets.

Types of caulk generally used on houses include:

  • Oil or resin-based caulk: The least expensive, but also the least effective. It is readily available and will bond to most surfaces. It tends to harden and crack after 2 to 4 years.

  • Latex and butyl-based caulk: A little more expensive, but much more durable than oil-based. It lasts from 6 to 20 years and holds up well to building expansion and contraction caused by changes in temperature. Latex is paintable and it comes in white or colored finishes.

  • Elastometric Sealants: Usually most expensive, but allows for the most building expansion and is readily paintable. Good to use on taller multi-family buildings that experience more movement and wind pressure. These sealants typically have a life of 20 years or more.

Directions for application will be on the tube and should be followed carefully. In general, about a half inch of the caulking cartridge nozzle should be cut off at a 45 degree angle and the tip should be punctured. Once the caulk is applied, you can finish the surface with a moistened finger or something smooth.

Apply caulking to all fixed joints, including:

  • Around windows and doors where frames meet siding

  • Between window sills and siding

  • Between frame wall plates and the foundation

  • Around all holes for pipes, ducts, or electric conduits through outside walls

  • Around all holes through walls, separating heated and unheated spaces, such as attached garages, storerooms, or attics.

  • Between unheated porches and the main body of the house

  • Where the chimney or masonry meets the siding

  • Around outside water hose faucets

Selection and Application of Weatherstripping

Weatherstripping performs a similar function as caulking but is used for movable parts, like the bottom of a window or door where the seal will be formed. Installing weatherstripping is also a simple process. All you will need is the contents of the kit you buy at a home improvement store. Keep in mind that this is being applied to a movable surface so you don't want to purchase a flimsy product that can wear easily.

  • Thin-spring metal weatherstripping can be used on both doors and windows. Though it is somewhat difficult to install, it is the most durable (and most expensive) type of weatherstripping. It is virtually invisible when installed.

  • Rolled or flexible vinyl is durable and easy to install. It is made with a metal backing for doors and without a backing for windows.

  • Felt and foam rubber weatherstrippings are inexpensive types that are easy to install. These materials are not very durable. Varieties with self-adhesive backing should not be used in locations where friction will occur.

 Air Sealing
 DOE Energy Savers - Caulking and Weatherstripping

Content updated May 28, 2009

Contact Us | PATH | Privacy Policy