Backer Rod is a backing for elastomeric and other cold-applied sealants. (such as chinking and caulking). It also helps control the amount of sealant applied for a proper seal, helps produce the ideal joint shape, and also acts as a bond-breaking strip. 
In Log Homes, backer rod serves a number of purposes: it provides insulation, acts as a bond breaker between the upper and lower log, and helps apply the chinking to the correct thickness. (1/4"-1/2" is usually best).

Backer Rod comes in three basic shapes: Round, Triangular, and Trapezoidal. All are available as a closed cell foam material.

Round is most often used to push into checks and cracks before log caulking is applied. It is also the least expensive of the closed cell backer rods that we stock.
Trapezoidal and Triangular shaped backer rod is used between rounds of logs giving the chinking a flat vertical surface to rest against and allows for a more uniform chinking depth compared to the round backer rod. 

Closed cell backer rod will not hold moisture, (actually repels moisture).
Provides a firmer finished joint than open cell foams
Comes in an assortment of sizes from 1/4" to 1-1/4".

Round Gray/Black closed cell polyethylene foam material used between the rounds of log work in your chinked style home or in larger checks/cracks in your logs that need to be filled. 
Chinking or caulking (for sealing checks) is used over this product.  
Can also be used around window and door openings where there is a gap between logs and opening bucks.

Note: Re: Shipping of reels of backer rod.
Reels are oversize and ship at a higher rate. Same with USPS mail.
Handypacks ship at true weight.
Additionally, 50' lengths take up considerably more space than the corresponding amount of product "on the reel". (e.g. 3/50' lengths of 1-1/4" backer rod will often ship as oversize or we'll send 2 lengths in one box and 1 in another to lower the overall shipping costs).

Product Data

cc0035-1-1/4-inch

50 feet      $  24.00
Reel-400'   $126.23

Photo courtesy of Sashco

Product Data

cc0035-1-inch

50 feet      $  13.50
Reel-550'   $101.16

50'              2 lb.
Handy Pak  4 lb.
Reel          15lb.
ships as oversize

50 ft.                $   6.00
Handipak-550'   $ 58.80
Reel-1550'        $119.64

50'              2 lb.
Handy Pak  4 lb.
Reel          15lb.
ships as oversize

50 ft.               $   4.00
Handipak-800'  $ 58.80
Reel-2500'       $135.80

50 ft.                $  3.50
Handipak-1400' $ 74.66
Reel-3600'       $136.64

50 ft.                $   3.00
Handipak-2500' $106.25
Reel-6400'        $183.11

Round Gray closed cell polyethylene foam: 

SOFROD combines the best of both open and closed cell foam backer rods for unprecedented performance in any joint sealing or glazing application.Unlike closed cell backer rods SOFROD is non-gassing when punctured; unlike open cell backer rods it is resistant to moisture absorption and freeze/thaw cycle problems. Because of its unique combination of low compression deflection, high compression recovery, and high tensile strength SOFROD has a ruggedness never found in open or closed cell backer rods. SOFROD easily conforms to irregular joints, limits the number of sizes of rod on the project.

 

Soft Rod is used between the rounds of log work in your chinked style home or in larger checks/cracks in your logs that need to be filled. 
Chinking or caulking (for sealing checks) is used over this product.  
Can also be used around window and door openings where there is a gap between logs and opening bucks.

Note: Re: Shipping of reels of backer rod.
Reels are oversize and ship at UPS 50+ lb. rate. Same with USPS mail.
Additionally, 50' lengths take up considerably more space than the corresponding amount of product "on the reel". (e.g. 3/50' lengths of 1-1/4" backer rod will often ship as oversize.
Product Data

cc0038-1-1/8-inch

50 ft.               $ 16.50
Handipak-120'  $  67.86
Reel-500'         $110.67

Photo courtesy of Sashco

Photo courtesy of Nomaco

cc0038-7/8-inch

50 ft.               $  11.50
Handipak-330'  $  62.03
Reel-850'         $123.90

Handipak  4 lbs.

Reel          15lb.
ships as oversize

50 ft.                 $  4.00
Handipak-1400'  $106.80
Reel-3600'         $197.78

Handipak  4 lbs.

Reel          15lb.
ships as oversize

White in color, this round closed cell backer rod is used for fishing lures. (and this is primarily why we offer it). Normally sold in small enough quantities that we ship this item by first class mail. 

Here's a really cool link to a site that will show you how to make "Steelhead Rags".
http://www.piscatorialpursuits.com/resourcecenter/rags.htm

White Round Backer Rod is a Polyethylene Foam backer rod that can be placed into the joint reservoir of expansion or contraction joints of old or new Portland cement concrete pavements before they are hot-sealed. 
Has a wide temperature rating, (-45 to 410 degrees F). 

cc0040-white

10 feet-$2.95
Available in:
 3/8", 1/2", 5/8"

Trapezoidal shaped white closed cell polyethylene foam material used between the rounds of logwork in your chinked style home or in larger checks/cracks in logs that need to be filled. Chinking or caulking (for sealing checks) is used over this product. Product comes in 4' lengths. Width is determined by the widest of the parallel faces.

Full cases ship as UPS os1 which means they're charged as 30 lb. rate.

Full cases ship from Oregon, Colorado and Tennessee Warehouses.

9 lbs.
ships as 72 lbs.

9 lbs.
ships as 72 lbs.

10 lbs.
ships as 72 lbs.

10 lbs.
ships as 72 lbs.

11 lbs.
ships as 72 lbs.

Each       $  5.90
Box 260'  $256.23

12 lbs.
ships as 72 lbs.

Each       $   7.39
Box 200'  $246.49

12 lbs.
ships as 72 lbs.

Each       $   8.68
Box 176'  $254.58

12 lbs.
ships as 72 lbs.

Each       $  10.40
Box 144'  $249.54

12 lbs.
ships as 72 lbs.

Each       $  12.78
Box 120'  $255.68

12 lb.
ships as 72 lbs.

TRI-ROD Backer Rod is a highly insulating, closed-cell polyethylene foam backer rod specifically designed and manufactured for use in the round log home industry. The triangular shape of TRI-ROD enables it to fit snugly between the logs and provides a flat surface for the optimum chink joint design. TRI-ROD is chemically inert, resists solvents, oils, and moisture. Because it does not adhere to sealant materials, it acts as a bond-breaker strip. TRI-ROD is odorless, non-exuding and nonstaining. The dense closed-cell structure of TRI-ROD makes it compressible and resilient
Triangular Shaped
Fits into the log joint to create a flat surface for chinking. 
Bond Breaker
Chinking releases from closed-cell surface allowing for its natural elasticity.
Rounded Corners: Increases chinking "footprint" area for maximum adhesion.
Closed-Cell: Resists moisture migration.
Flame Retardant: Withdraws from flame rather than supporting combustion.
Energy Efficient: TRI-ROD has an R 4 per inch rating giving it excellent thermal efficiency. 
No Outgassing: Does not outgas or cause blistering.
Non-Toxic: Is odorless and safe for exterior and interior use. Has excellent flame and smoke ratings per ASTM-E-84. 
Ease of Application: Is easily installed between logs after spraying back side with spray adhesive. It is not necessary to hold TRI-ROD in place with nails, staples, etc.
Flexible: Provides firm but flexible chinking surface; will not distort or result in bulging, uneven chinking surface.
Testing: Meets or exceeds ASTM standards for polyethylene foam insulation. See Properties & Performance Comparison of Backing Materials. 

Installation Guidelines