Basic Guidelines

Guidelines are given in very general terms due to the wide variety of tanks that can be lined. Read instructions completely before you begin. If you need further clarification, call and ask to speak to an installer or someone familiar with installation procedures.
PVC liners are made oversized to allow for long term shrinkage. They need to be installed with the wrinkles and gathers in the material spread evenly throughout. Synthetic rubber liners, such as Hypalon, XR-3 and XR-5, do not shrink and, consequently, are manufactured with closer tolerances. They will be installed with a tighter fit.
The following information covers installation of a PVC liner in a round concrete tank with notations relating to square or rectangular shapes and rubber liners. Separate instructions are printed for liner installation in metal and wood tanks. Not every example is covered.

A Little Forethought

A little forethought on supplies needed during installation can save many hours of climbing in and out of the tank. Organize your tools and supplies. In addition to the liner and underlayment, you may need some of the following:

1) Drop light or strong flashlight needed in enclosed tanks (*Lights will burn through some liner material very quickly. Do not allow lights to lay on liner material when turned on.);
2) Step ladders or full height ladders plus padding to be used beneath the ladders to protect the liner. Generally you will need at least two ladders;
3) Extension cord;
4) Drill and grinder;
5) Applies only if there is a usable wood sill - 3" X 3" X 1/2" plywood squares (size can vary) for temporary attachment of liner and underlayment to the sill;
6) Double headed nails (removable type) for temporary attachments into wood sill;
7) Stainless steel ringshank nails for permanent attachment to wood sill or anchor bolt for attachment directly into concrete;
8) Predrilled stainless steel bar or HDPE attaching bars. *Please note, stainless steel is recommended because it pinches the liner tighter to the tank;
9) Tank nipple sets, flanges, shroud kits, etc. needed for each inlet or outlet;
10) Pipe wrenches;
11) Hammer;
12) Measuring Tape;
13) Permanent marking pen, fine or medium point;
14) Scissors and/or utility knife;
15) Vinyl repair kit for PVC liners;
16) Hypalon glue and xylene for Hypalon liners and/or Hypalon repair patch;
17) Hot air gun for Hypalon, XR5, XR3, etc.;
18) Gloves;
19) Clean rags;
20) Masking tape;
21) Rectorseal;
22) Silicone;
23) Ground fault interrupter (GFI);
24) Rubber soled shoes;
25) Means of communicating with the outside, such as two-way radio, cell phone, etc.

1. Grind smooth all sharp points.
2. Fill all wide cracks and plumbing openings that will not be reused.
3. Screen overflow.

Drain tank. Remove any sediment and debris from bottom and rinse or sweep clean. High pressure washers, if used, should be used with extreme caution. Damage can be accelerated in some tanks. In small tanks it works well just to rinse the walls using a bucket of water and a new platic bristle broom or a hose with running water and a push broom or a 2'-3' squeegee.
Place ladders and equipment in tank. Feet of ladders should be padded and base of ladders should always be supported by a second person when anyone is on a ladder.

Underlayment in Concrete Tanks

Before a liner is installed in a concrete tank WITHOUT a wood sill, drill tank, install anchor bolts and hang the underlayment. The predrilled stainless steel bars are to be used as templates for drilling your tank as follows:


Separate your underlayment for walls and floor. Cut your floor panels to the floor configuration. Excess underlayment can remain in the tank if you so desire. You can tape or silicone the panels together if it makes it easier to hang. Check wall sizes to determine how much overlap you can have in the panels or all excess underlayment can be used on the last panel installed.
Hang your underlayment on each of the bolts approximately 1/2" down from the top. Underlayment should overlap at the beginning and ending of each panel by at least a few inches to a foot or more.
Mark your tank wall in quarters and number the markings #1, #2, #3, and #4 for round tanks.

Installing the Liner

In concrete tanks plumbing generally is not removed. It is possible that some modifications may be required to obtain a seal to the tank liner where plumbing is attached.
When the liner has been manufactured from supported materials such as Hypalon or XR-5, all steel washers from the tank nipple kits must be installed against the inside of the tank wall before the liner is installed. Supported materials will not stretch. With PVC liners, because material is stretchable, this step can be done after liner is installed and permanently affixed to the tank as described in Step #6.
Unfold liner from the center of the tank towards side wall. Locate the bottom seam of the liner 1"-2" up tank wall instead of against the tank floor.
Locate any vertical side seam of the liner. This is your starting point. Mark your liner in quarters and number the markings #1, #2, #3 and #4. Align liner seam to the beginning quarter mark on your tank. Using a plumb mark, align liner seam to the top of the tank as well as the bottom of the tank. If you begin with everything in alignment you should continue in alignment throughout the entire installation procedure. This will also assure even gathers around the top perimeter during the installation procedure eliminating guesswork. For square or rectangular tanks, mark corners of the liner.
In concrete tanks with a wood sill, temporarily attach the sidewall to the top of tank using small plywood squares to pinch the liner to tank. In concrete tanks without a wood sill, the temporary attachment is made using your concrete anchor bolts.

Caution: Be sure not to lift the liner wall too high as it will lift the bottom of the liner off the floor. Damage to the liner may occur after it is filled with water due to too much stress and weight on the bottom seam. The liner should be installed in a relaxed fashion and a small amount of "blousing" all around the bottom of the tank wall is recommended.

After you have completed the temporary attachment of the sidewall at the vertical seam (your starting point), go directly across the tank and raise the wall for second temporary attachment. Your #3 mark on the tank wall and liner should be aligned. When you have an even amount of wall draped behind you, make the second attachment as previously described. Make two more temporary attachments at the quarter mark #2 and #4. Even amounts of liner materials should be temporarily attached around the entire perimeter.
Permanently secure liner to top of tank using predrilled stainless steel or a high stress HDPE bar or some other suitable bar type material. In concrete tanks with wood sill use stainless steel ringshank nails and nail through each predrilled section of the bar, through the liner and into the wood.
In concrete tanks without a wood sill, place and anchor each predrilled bar in numberical order and in the correct direction >> as previously marked on each bar. Disconnect each temporary attachment as you make the permanent attachments. Allow excess material to fall back over the attaching bar into the tank. You only need to trim the excess material where it may come in contact with any plumbing such as your overflow.
The following is one of the most critical in the installation procedure. Locate and plumb the bottom drain and/or outlet. If inlet/outlet is in good condition and pipe threads of nipple extend into the tank sufficiently to attach the soft washer, hard washer and nut, it will not be necessary to replace it.
If inlet/outlet is an unthreaded pipe and is in good condition and extends into the tank at least 1 1/2" or more, you may install a shroud (also known as a sleeve) after you cut the hole for the plumbing.

When cutting holes in the liner for outlets or drains make sure there is no pull on the bottom seam of the liner. The seam line, where tank and floor are welded together, should be located 1"-2" up the tank wall. This is more important with PVC liners than Hypalon or XR5 liners simply because PVC shrinks over a period of years. As it shrinks, the liner seam line should end up on the floor if you have installed it correctly. You want to avoid having the liner seam shrink away from the tank and then carry the weight of the water since that could eventually result in a leak.

*No instructions are given for installing flanges or stainless steel ring kits, only tank nipple kits since that is the most commom plumbing in tanks. Call for further instruction if needed.
Cut a hole in the liner to the inside of the tank nipple (cut in a round configuration, no straight line which tears easily) to assure a nice fit. Other directions will apply when installing shroud kits.
Remove old plumbing and replace with new plumbing if needed. The tank nipple set has the placement of all the washers and nuts exactly as they will be installed. Leave one hard washer and nut on tank nipple and insert from the outside of the tank with hard washer and nut against the tank wall on the outside. From the inside of the tank gently slip one hard washer through the hole in liner and place against the tank wall. If using a Hypalon or XR5 liner, the hard washer should have been installed before liner was installed as previously instructed. Follow with soft washer. Slip liner over tank nipple and up against the soft washer. To the inside of liner place soft washer over tank nipple and against the liner, then hard washer and pipe nut. On the outside of the tank you should already have in place one hard washer against the tank plus the pipe nut. Hand tighten pipe nut on inside of tank using caution not to over tighten. Do not allow pipe to turn while tightening nut. You may need to have someone on the outside of the tank holding the tank nipple so it does not turn. This will cause the liner to twist on the inside of the tank and a leak may result.
After attachment has been completed and tightened, seal with Rectorseal (available at most hardware stores) around the top of the nut where it meets the threads and around the bottom of the nut where it is against the hard washer. Water can travel down the pipe threads allowing leaks to occur to the outside of the tank if this procedure is not completed or is completed incorrectly.
******This step does not apply if the shroud was factory welded to the liner.

Shroud kit attachment. Place soft rubber seal over end of pipe. It should align with the end of the shroud when installation is completed. Slip shroud over pipe and rubber seal until the extended base of shroud is flat against the liner. In PVC liners, follow instructions for gluing. Different method of attachment is needed when gluing Hypalon which requires Hypalon glue, xylene, teflon roller and hot air gun. XR-5 material cannot be glued, method for attaching shroud will be with a hot air gun only.

Take a predrilled bar and mark #1 on it and #1 at the TOP of the tank wall where you start. Mark a vertical line on your tank with start and ending point of your first bar. You must put the bend in the bar same as tank curvature. You need a person at each end of the bar to hold it in position as you drill the tank wall using the bar as a template. The holes in the bars must match the holes drilled in the tank. Mark an arrow on the bar for direction of install. Insert a bolt into the first hole to hold the bar in place as you drill. Insert a bolt every 3rd or 4th hole to maintain the proper alignment. Take the bar down and set it aside. Start procedure over with a second bar leaving approximately 1/4" to 1/8" between bars. Repeat this step until the entire tank circumference has been drilled. Be sure to mark every bar in the order that you use it #1, #2, #3, etc. and the direction of install >> along with marking corresponding numbers and end marks on tank wall. You will also be marking your tank in quarters so you may find it easier to mark the bar with A, B, C, or 1a, 2a, 3a, etc.
For overflow, follow procedures previously detailed. Overflow should be located several inches below top of liner. Relocating overflow may be necessary in some cases.
Silicone the area where underlayment is exposed at the top between tank wall and liner. If not done, moisture that collects on the roof and top wall of tank will run down through the underlayment between tank and liner.
After shroud is glued or attached to the liner, place stainless steel hose clamp over end where soft washer is located and tighten. Seal between pipe shroud and rubber seal with Rectorseal.
If you have any questions or run into a problem during installation, we encourage you to call and speak with someone familiar with installation procedures. Our toll free number is 1-800-523-8853.


A specialty liner fabricator and installer since 1971. California contractor's license #618911.