Strength and Benefits Using 2-3/8" Pipe Vs 1-7/8"

​Between 2002 and 2008 1-7/8” Schedule 40 pipe was in use with those that preferred the pipe/ post mount install system with vinyl fence mostly due the available post mounting devices at this time. When Slip Mount System introduced it's 2-3/8” post mount device in 2009 offering an improved performance both the internal pipe, vinyl post and the entire fence system having more strength overall.

This is what now made the 2-3/8" pipe a better choice!

  • 2-3/8" pipe is 1/2" larger in diameter, so by increasing the diameter of the pipe we increase the pipe's strength!
  • 2-3/8" pipe allows over 1-1/2" of bottom vinyl rail insertion on either side of pipe inside 5" x 5" vinyl fence post's cavity!
  • Greater Bending Moment of strength i.e. ​2-3/8 pipe 0.095 wall thickness has almost double the BM strength due to its larger diameter. (see chart)
  • Less expensive, even our suggested minimum wall 2-3/8" (0.079) pipe performs in wind with use on privacy fences 5 Ft and 6 Ft tall 8 Ft O/C. 
  • Better ground anchor, more below ground soils and material travel up inside the 2-3/8" pipe cavity during post driving adding more anchor weight.
  • Contact and grip, 2-3/8" pipe offers 24 sq inches of outside pipe surface in contact with below ground soils, preventing up lift or frost heaving.
  • More rigid, 2-3/8" has less flex a top of pipe when pipe is driven 4 Ft below grade and left 4 ft above grade, entire fence moves less in wind.  ​​

Fig. 1

​​Slip Mounts with other vinyl post structures such as sign posts, arbors and pergolas?
When using Longer pipe and vinyl posts use 3 or 4 Slip Mounts per pipe. 

So how long has this install system been around?​

Patent searches reveal many pipe to post mounting systems and devices had been in use for the propose of fixing or mounting wood and other materials to an upright pipe dating back over 50 years ago, however It was not until the vinyl fence industry grew in popularity and by 2002 we first seen the use of a pipe to post mounting system designed specifically for PVC fence posts. One of the original was referred by many as the “Star Post Adapter” invented by G. Elsasser, (see Fig. 1) Elsasser's design was created in having a center cavity, circle or square this allowing  square tube or round pipe fitment also having had 4 extended fins or points formed like a star in order to fit a hollow square fence post profile, one would simply to fasten on (2)  Star shaped adapters to an upright pipe using screws and sleeve over with a hollow PVC fence post.


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        Questions about products

  • Where are Slip Mount System products made?  Our manufacturing plant is located in Calgary, Alberta, Canada.​
  • What material are they made of?  We use a 100% pure form thermoplastic resin that is BPA free, no phthalates, heavy metals or allergens.
  • Are Slip Mounts soft, rubber like?  No, they are hard and more rigid,material offers high strength-to-density ratio and withstands maximum stress.
  • Will Slip Mounts break in the cold?  The material is impact resistant, similar to Puck Board using strong intermolecular forces and tensile strength. 
  • How many years has slip Mount been on the market? Slip Mount Device is a US Intellectual Property Protected Design D630085 2009 
  • Do you ship to the USA?  Yes we distribute our products both in Canada and the USA.
  • Who do you sell to?  We sell to large wholesale distribution chains, fence companies, contractors as well end user consumer at various price levels.  
  • Will Slip Mounts Fit all 5" x 5" Posts?  The Slip Mount device is a universal fit to the industry standard or Econo wall 0.130 to 0.135 post wall thickness.  

        Questions about Installing 

  • Should I use 2-3/8" Pipe or 1-7/8" Pipe on a new install?  Definitely use 2-3/8" pipe when installing vinyl fence (See all the benefits below)
  • What length of pipe and wall thickness?  8 Ft length is most common with 5 Ft and 6 Ft high styles and 2-3/8" x 0.079 wall thickness pipe minimum. 
  • How deep is the pipe driven into the ground?  With 5 and 6 Ft Fence high styles, pipe is set 4 Ft below grade to a minimum depth of 3 Ft depth.
  • How high should the pipe stick out of the ground?  Approximately 4 Ft above ground both with 5 and 6 Ft styles of vinyl fence. 
  • Do Slip Mounts screw onto the pipe?  Yes, Slip Mounts have upper and lower mounting flange, providing a mounting area to fasten on screws.  
  • How much adjustment will the Slip Mount provide?  On 2-3/8" Pipe with 5" x 5" Post's it provides up to 1-1/4" and 360 degrees of adjustment.
  • What about portable Post/Pipe Driving Tools, where do I get one? Many are available at rental centers or you may purchase form a manufacturer.

             Web Links to portable gas pipe drivers SKIDRIL RHINO TOOL REDI DRIVER  * TITAN  

  • Will Slip Mount fit 1-7/8" Pipe?Yes we also make a reducer insert that fits inside the Slip Mount and will adapt the 2-3/8" cavity to fit 1-7/8" pipe.
  • Can I use Slip Mount with pergolas, arbors and sign posts? Yes when using longer pipe and taller vinyl posts use 3 to 4 Slip Mounts per pipe. 

​*  Note when using 1-7/8" pipe and Slip Mounts along with our "Reducer Insert" it is recommended using Schedule 40 industrial grade pipe in all privacy applications. The use of 1-7/8" with light commercial grade is best suited for decorative or ornamental vinyl fence styles having less wind load. ​