Materials

Applications

Pros and Cons

Caulks

Siliconized Acrylic Latex

• seal cracks and holes up to 1/2 in. wide
• seal sole plates to subfloor, rough openings to window frames, drywall to framing or masonry, and drywall to electrical boxes
• high volume users consider a professional grade refillable caulking gun

• adheres well to clean, dry surfaces of wood, metal, drywall and masonry
• readily available
• inexpensive
• paintable
• may not adhere in cold or damp conditions
• clean up with soap and water

One-Part Polyurethane

• same as above, plus seal concrete expansion joints
• can be applied to joints up to 2 in. wide if done properly.

• extremely good adhesion to almost all surfaces
• applies in temperatures down to 0° F if caulk is kept at 60° F or above
• applies to damp, but not saturated or ice-covered, surfaces
• very elastic and flexible -- will stay in joints even with substantial movement
• poor adhesion to glass
• more expensive than siliconized acrylics
• clean up with chemical solvents

Silicone

• most silicones are "acetoxy" cure. They release acetic acid as they cure, which can weaken the surface of concrete and corrode galvanized metal. Acetoxy cure products have a characteristic vinegar smell. "Neutral" cure silicones are more expensive, but are also more flexible and work on concrete and metal substrates.

• very elastic and flexible
• good adhesion to glass
• clean up with chemical solvents
• most can't be painted

Adhesives

Construction Adhesive

• seal subfloor sheathing to joists
• seal tongue-and-groove edges of subflooring

• on job site during floor construction
• not flexible

Drywall Adhesive

• seals drywall to plates and studs if applied in a continuous bead

• already on the job site
• adds little to drywaller time
• method has not been blower door-tested
• not flexible

Foams

High-Expansion Urethane

• seal cracks or holes up to 3 inches wide
• seal odd-shaped holes
• seal rough openings to windows and doors, seal plumbing and electrical penetrations

• large canisters with adjustable nozzles are convenient and allow adjustment of foam bead for 1/4 in. up
• adheres well to any material except slick plastic, such as polyethylene
• foam expands to fill hole shape
• avoid getting foam on metal window frames
• avoid overfilling around windows and doors -- may warp frames

Low-Expansion Urethane

• same as high-expansion

• low expansion allows better control
• reduces potential to overfill cavities
• eliminates stress on window and door frames
• reduces cleanup from overfilling

Gaskets

Polyethylene Backer Rod

• seal cracks from 1/4 in. to 2 in. wide
• seal at rough openings to windows and doors, especially for wood or vinyl windows
• use 1/4 in. diameter between drywall and framing
• use in deep cracks (greater than 1/2 in.) to back caulk

• can be applied in any temperature
• can be applied to wet surfaces (staples on)
• inexpensive
• clean -- no gunk on tools or tapes
• once fully compressed, may not recover -- avoid using where joint will move

Polyethylene Sill Sealer

• use between mudsill and basement foundation wall

• prevents water wicking up from concrete
• avoid using under wall bottom plates

Foam, Neoprene,
EPDM and Other Building Gaskets

• use between drywall and framing
• use between nailing flanges of metal or vinyl windows and rough openings
• use on attic and crawl space hatches
• use between all major framing members

• staples on -- can apply in any weather or on wet surfaces
• rolls easily
• requires care to apply drywall
• highly elastic -- recovers well when compressed
• clean

Sheets

Rubber or Neoprene Sheet Membranes

• seals plumbing stacks and pipes to wall plates adjacent to unheated spaces (attics, crawlspaces, etc.)

• allows pipes to expand and contract without breaking seals

Housewrap

• can be used for sealing complicated leakage sites, such as stairs on outside walls, soffits and dropped ceilings
• fully-wrapped walls can connect to the air barrier on inside ceilings and floors

• durable
• vapor permeable, so it can be used on the outside surface of walls

Polyethylene Sheets

• can be used for sealing complicated leakage sites, such as stairs and tub enclosures on outside walls

• not vapor permeable, so it must be used on the warm side of the exterior barrier