Log Home Sealant Tapes

Self-expanding, precompressed foam sealants. Classic LogHomeTape and Acrylic LogHomeTape

Emseal log home sealants are self-adhering tape seals made from resilient, open-cell polyurethane foam impregnated with a water-based acrylic-modified asphalt emulsion (Classic LogHomeTape) or a water-based, acrylic impregnation (Acrylic LogHomeTape).  They replace and outperform liquid sealants, butyl-tape sealants and closed-cell foam tapes.

Emseal log home tapes have been the sealants of choice of handcrafters and machine milled log home manufacturers and discerning erectors worldwide for more than 30 years.

How it Works – The EMSEAL Advantage

The open-cell foam is impregnated, compressed  and shipped in reels. The stored strain-energy of compression in the foam means continuous back-pressure is exerted against surfaces to be sealed. This pressure, combined with the adhesive nature of the impregnation, assures reliable adhesion to both substrates. As the logs shrink and expand with seasonal temperature and humidity changes, long-term sealing contact with the log surfaces is maintained.

At installation the tape is held to a level of compression suitable to the intended application. The gap between the top of the tongue and the bottom of the groove in milled logs sets the size of the LogHomeTape to be used. In hand-crafted construction, particularly scribe-fit, a thicker tape is usually selected to fill the varying void behind the nesting point.


Log Home Sealant Tapes

Self-expanding, precompressed foam sealants. Classic LogHomeTape and Acrylic LogHomeTape


  • Permanent elasticity/memory enables it to fill gaps caused by changes in log size (shrinking and settling)
  • Continuous backpressure enables the foam sealant to fill contours and irregularities
  • Maintains weathertight seal and thermally insulates over extreme temperature ranges
  • Does not dry out, become brittle or crack
  • Unlike putty-type (butyl) and liquid sealants which squeeze-out under compression, LogHomeTape compresses into itself and remains in place between the logs where it is needed.
  • Resistant to ultraviolet light and ozone
  • Does not cause “log-float” (suspension of logs by airfilled cells of closed-cell gaskets)
  • Easy to install with mounting-adhesive on one side—strong polyester scrim embedded in adhesive resists stretching of material during installation
  • Highly resistant to vermin (bugs, rodents, birds, etc.)
  • No ozone-depleting chemicals used in manufacturing and contains no volatile organic compounds (V.O.C.’s)


EMSEAL Log Home Tape is available in a variety of sizes and widths. The size is the compressed “thickness” or “height” of the tape that matches the final anticipated opening of the joint after allowance for shrinkage and settlement. At this point, the correctly sized foam seal will be compressed to ¼ or 25% of its uncompressed dimension for weathertight performance.

Available compressed thicknesses:
3/32″ (10mm) up to 2″ (50mm)
Equivalent expanded thickness:
3/8″ (10mm) up to 4″ (100mm)

Available widths:
3/8″ (10mm) up to 3″ (75mm)

Download product size chart (pdf)


In log home construction, the sizes of the gaps between and at the end of the logs is changing constantly. This is due to various factors including:

  • drying out of the logs
  • changes in relative humidity
  • settlement

The effects of these variables are significant. Even with kiln-dried logs, further drying out over time causes log shrinkage resulting in changes in gap size between logs. The effects of daily and seasonal changes in relative humidity will likewise affect the gap size at any given time in different parts of the structure.

Settlement will result in significant joint gap size changes, particularly above doors and windows where the structure above settles downwards while the door or window mullion remains at its original level.

These movements as well as movement caused by less predictable factors such as wind and vibration must be accepted and accommodated by a good sealant.


Classic LogHomeTape: Black
Acrylic LogHomeTape: Grey


As a sealing and insulating gasket between logs:

  • Machine milled tongue and groove
  • Scribe fit handcrafted

As a corner gasket for:

  • Saddle notches
  • Corner overlaps

As a settling gasket above:

  • Windows
  • Doors

As a secondary seal to:

  • Liquid sealants
  • Chinking

As a sill gasket

The following indicates levels of sealing at respective installed compression levels:

Emseal sealant tape compression and sealing level chart

Classic LogHomeTape  is by volume the most widely used. Black in color as the result of it’s acrylic-modified asphaltic impregnation, AST affords economy without sacrificing performance and is widely lauded by log home builders for its robustness and durability. Asphalt has been the choice for sealing ships, roofs, foundations, roads and many other structures throughout history. As a result it is not unreasonable to expect that EMSEAL Classic LOGHOME TAPE will last the life of your log home.

Slightly more expensive, Acrylic LogHomeTape features the latest in 100% acrylic chemistry and is grey in color. Choice of Acrylic over Classic is really a preference of the user for color and chemistry.

The correct choice of a sealant for the horizontal joints in your log home is as important as your final choice of species of wood. WHY?
• The cost of trying to reseal a log home if the sealant fails, far outweighs initial sealant costs
• The incremental cost of using a high performance sealant during construction may be saved in energy
costs alone in the first few seasons.
• High performance sealants, correctly sized and installed are “lifetime” sealants.

Most expanding gaskets are made of either closed-cell or open-cell foams. Exceptions are butyl tape and liquid sealant that relies on adhesion to the log to pull them open.

Closedcell foams are less suitable as seals because their individual cells are essentially gas bubbles which tend to deflate over time. Known as “compression set” this failure to recover typical of closed-cell foams results in the failure of the product to fill and seal changes in gap size caused by movement.

Open-cell foams that have been filled with an impregnating sealant, on the other hand, retain their sealant and recovery properties when compressed to as little as 12% of their original uncompressed dimension.


• Backpressure – The pressure exerted by the seal against the log surfaces. This must be sufficient to
cause the seal to expand as a gap opens but not so great that it causes “log float”.
• Recovery – This indicates how completely the foam recovers to its original dimension after extended
compression. The higher the recovery percentage, the better the seal.
• Durability – This includes the ability to resist ultra violet light and ozone exposure that can cause brittleness, cracking and ultimately seal failure.
• Wood-Preservative Compatibility – Some foam sealants can be applied to treated wood, others only
to wood that has not been treated. The foam sealant should work with preservatives, whether applied
before or after installation of the seal.
• Ease of Installation – Some foams are self-sticking, with removable release for easy installation.

Sealant sizing: Perhaps one of the most costly mistakes made in log home sealing is to undersize the preformed sealant used between horizontal log courses. The sealant should match the joint-gap size after settlement and shrinkage have been allowed for.

High performance sealant vs. low-cost short-life alternatives:
High performance sealants, properly sized and applied are the better choice. Consider the cost of routing-out and replacing old sealant against the up-front cost of a high
performance sealant.

Check available sealant depth: As the tape width is increased, so does the ultimate margin of safety. However, tape width is also determined by the tongue and groove or other configuration present. Ensure that within these parameters maximum use is made of tape width.

Correct sealant termination: If your log home had no openings (i.e. windows or doors let into the walls), then the correct sealant configuration would be continuous seals running completely around each log course. This means that at each corner the sealant would be lapped to provide suitable horizontal seal integrity. Since openings are present in the structure for doors and windows, seal integrity must be preserved both, horizontally and vertically. Care must be taken to ensure that horizontal and vertical seals terminate into one another.

Double vs. single sealant System: It is generally accepted that the use of a double gasket system is preferable to the use of a single gasket system. A “dead-air” void is created between the two seals which greatly enhances the thermal insulation properties of the log home.

Sealant positioning: Good joint design provides for the seal to be positioned at a high point in the joint detail so that as much as possible, water tends to drain away from the seal

It had long been considered impossible to achieve Alaska’s highest energy-efficiency rating in a log home. That is until a home was sealed with two strips of EMSEAL LogHomeTape between and at the end-joins of the logs, and with large-size LogHomeTape as compression gaskets in the settling voids above windows and doors.

The result was the first-ever 5-Star, “very efficient” rating for an Alaskan log home.

At settlement joints above windows and doors, LogHomeTape compression gaskets were used to provide excellent insulation and air-infiltration from the outset and are installed in conjunction with a vapor barrier membrane. Over time they’ll compress to a point where long-term watertight sealing is achieved.

The home energy rating is a standard measurement of a home’s energy efficiency. An energy rating allows a home buyer to easily compare the energy costs for homes being considered. The home receives a point score between 1 to 100, depending on its relative efficiency. An estimate of the home’s energy costs is also provided. The home’s energy rating is then equated to a Star rating ranging from a 1 Star for a very inefficient home to a 5 Star for a highly efficient home.

Log Home Sealant tape saddle notch with sheeps wool insulation EMSEALIn most applications, LogHomeTape can be laid to follow saddle notches and corner overlaps. In special conditions, Emseal can make corner pads or pre-cut gaskets to seal at corners. Contact us to discuss the unique ways in which sealing these critical areas can be handled using LogHomeTape.

1. Storage and Surface Preparation
Tape should be stored in a warm dry interior location. Ideal application temperature is approx. 75°F (24°C). Expansion will be faster at higher temperatures and slower at lower temperatures.
Tip: For faster expansion in cold conditions keep the material warm before use and, if desired, apply heat from a hair dryer to installed material to accelerate expansion. Joint faces should be dry and cleaned of dirt, oils, grease, etc. There should exist sufficient depth to receive full width of the sealant.

IMPORTANT: Reels must be stored FLAT and kept compact. Should material expand in package it can still be used. Unroll material, allow it to expand, then recompress it between surfaces to be sealed.

2. Opening Reels
Only open materials that will be immediately used. Remove shrink wrap.

Cut in front of colored marking tape and pull back release liner to expose mounting adhesive.

3. Square Off Ends
Start and finish ends must be cut square. For easier cutting spray knife or scissors with mist of water.

4. Peel Off Liner
Remove release liner to expose adhesive face of tape.

5. Adhere to Surfaces
Press adhesive face to one surface. Align other surface with tape. Secure surfaces together. Tip: If needed, cut and fit small filler pieces of tape to fill panel corrugation or voids.

6. Joining Lengths
Overlap one piece of tape with another. Cut through both pieces at a 45-degree angle with a long-bladed knife. Reposition mitered faces over each other and pinch them firmly together to make a join.

Available in many sizes.
If this tape size does not return the results you desire in your specific application, ask your vendor or Emseal for other size options.

• Will not adhere to components that are dirty or dust covered or to surfaces coated with oils or other release agents.
• Will expand to follow and fill irregular substrates within reason. Sharp corners and acute angles may need to be filled with additional filler pieces  in order to ensure a proper seal.
• Substrate must be capable of resisting, without bending or deflection, approximately 1.5 to 2.5 lb/in2 (10 to 17 kPa) back pressure from the tape.

Available for shipment internationally.
Prices are available directly from the manufacturer.
The product range is continually being updated, and accordingly EMSEAL® reserves the right to modify or withdraw any product without prior notice.