GacoFlex LM-60 Liquid Applied Urethane Waterproofing Membrane

PART 1 - GENERAL

LM-60 is a two component, 100% solids liquid applied rubber that cures by chemical action to form an elastomeric membrane. It is used as a waterproofing membrane over concrete, metal and plywood.

LM-60H is used on horizontal surfaces in a between slab or below grade configuration. Application is by notched trowel or squeegee in one coat or sprayed, if thinned, in two coats. The membrane is covered with a protection course and a wearing course of concrete, blacktop or pavers.

LM-60V is thixotropic in consistency and will cling to vertical surfaces without run-off at normal application rate. It may be applied with a trowel in one application or sprayed, if thinned in two coats.

The component ratio for LM-60 is 15:1 by volume. The two components must be mixed thoroughly and completely as outlined in these instructions.

A. Storage of Material:

All material must be stored in the original unopened containers and all containers must remain lidded unless they are actually being used. Storage areas must be protected from direct sunlight, rain, or snow. The storage areas should be held at temperatures above 60°F (16°C). While containers are at the job site they should be covered with polyethylene or similar waterproof sheet if exposed to the weather. Water, snow or ice in either the Part A or Part B will ruin the material.

B. Safety:

When working with Part B, avoid contact with skin and eyes. If contact occurs, wash skin with water or alcohol; flush eyes immediately with large quantities of water and get medical attention. Do not smoke during mixing, application, or in the immediate area if thinners are used until all solvents have disappeared.

C. Application Conditions:

Application temperatures are limited to above 40°F (5°C). Material shall be stored until time of use at temperatures above 60°F (16°C) to maintain a suitable consistency for easy mixing. NO application shall start or proceed during rain or snow. Installed material should not be exposed to surface moisture for a period of two hours after application.

D. Substrate Condition:

All areas to be coated must be free of dust, dirt, oil, grease, paint, and othercontaminants. All areas to be coated must be thoroughly dry and free of dew or frost.

E.Substrate Construction:

1. Concrete: See specification guide GW-2-1 for recommendations regarding construction, finishing, and curing of various types of concrete.
Plywood: See specification guide GW-2-3 for recommendations regarding the installation and selection of the proper grade of plywood. Consideration should be given to separate engineering evaluation of structural loading and support requirements.

PART 2 - MATERIALS

A. Urethane Coatings:

Gaco Western LM-60H for horizontal surfaces and LM-60V vertical.

B. Concrete Primer/Sealer:

Gaco Western urethane primer U-5677 and GacoFlex two component Epoxy Concrete Sealer E-5320.

Alternate Concrete Primer Sealer: Gaco Western E-5481 two component 100% Solids Epoxy concrete primer/sealer.

C. Metal Primer:

Prime metal surfaces according to Gaco Western's "Primer Recommendation Chart."

D. Flashing and Joint Reinforcing:

GacoFlex NF-621 neoprene sheet flashing and related materials as required for flashing drains, base angles, etc. Consult Gaco Western GW-1-2 for specific recommendations.

Tape: 66R 2" wide release tape.

E. Sheet Flashing Adhesive:

Neoprene N-1207

PART 3 - PRIMING

Priming is to be done prior to both flashing and membrane application (except do not seal coat with thinned LM-60 wherever neoprene sheet is to be installed). Surfaces should be free of contaminants.

A. Metal Surfaces:

1. Ferrous Metals, Aluminum: Apply E-5320/E-5325, thinned with one pint of water to the gallon (.5L per 4L), at a rate of one gallon per 200 to 250 square feet (4.1 L / 20-25 m2). Allow primer to dry completely before application of flashing adhesive or membrane. Dry time is two to three hours minimum.
2. Copper: Prime with U-5677 primer at the rate of one gallon per 300 square feet (4.2L /30m2). Allow to dry. U-5677 must not be exposed to moisture and must be over-coated within four hours.

B. Concrete Surfaces:

1. Sealing: Concrete surfaces do not require a primer to obtain adhesion. It is frequently necessary to use a sealer coat of thinned LM-60 to prevent pinholes and blistering occurring in the coating, which is caused by air entrapped in the concrete when covered with a full 60 mils (1.5 mm) of coating. Dust or powdery concrete may also cause pinholes and the sealer coat is recommended. The sealer solution is made by adding one gallon (3.8L) thinner to one unit of LM-60 during the original mixing process. This solution is applied preferably by roller, or spray to effectively seal the surface and covers approximately five gallons per 600 square feet (19L /46m2) mix.
2. Primer-Sealer System: Consideration should be given to the application of the Gaco Western primer-sealer system when waterproofing exterior concrete decks that will experience solar heating during application. A phenomenon known as concrete outgassing may occur which causes blisters and pinholes in the applied coating. The use of the primer-sealer system is the best method known for prevention of blisters and pinholes. See General Instructions GW-2-2 for proper application recommendations.

C. Plywood Surfaces:

Plywood does not require priming.

PART 4 - MIXING

1. LM-60 is packaged in four-gallon (15L) kits. Each kit consists of 3-¾ gallons (14.2L) Part A black and 1 quart (.9L) Part B in a separate container. Each kit provides sufficient material for 100 square feet (10m2) at 60 mil (1.5 m).
2. If either container has been leaking or contains water, do not use it. When opening the pail take care not to allow any water to enter.
3. To mix, remove the Part A lid and stir to suspend any settled pigment. Slowly pour the Part B into the Part A while mixing, being very careful not to spill or splash any material. Power mix thoroughly for a minimum of five minutes. Scrape the pail sides thoroughly to aid complete mixing.
4. For mixing quantities to yield less than four gallons (15L) (one kit) combine fifteen volumes of Part A with one volume of Part B.
5. Power mixing is mandatory. Use a power mixer that will thoroughly agitate the mix (electric or compressed air powered). A jiffy mixer PS 21 or M-61A KOL mixer have been found to be adequate.
6. If material is to be sprayed or used as a seal coat add ¾ to 1 gallon (2.8 to 3.8L) thinner after adding Part B and blend together as directed above. Do not use thinner if material is not to be sprayed or used as a seal coat.
7. Once the LM-60 is thoroughly mixed, it has an approximate pot life of one hour at 70°F (21°C). Higher temperatures will shorten pot life. Lower temperatures will lengthen pot life. The pot life can be extended to three hours by thinning at the time of original mixing (up to 10%).

PART 5 - FLASHING AND JOINT TREATMENT

A. Non-moving Cracks in Concrete:

Stripe coat all non-moving cracks. Fill the crack first with LM-60. After filling apply LM-60 for a distance of 3" (8 cm) on each side of the crack 60 mils thick (1.5 mm) (1/16") and allow to cure. When applying the membrane on the main field of the deck, go over the stripe coat to achieve a total thickness of 120 mils (3 mm) (1/8").

B. Control Joints and Moving Cracks:

Remove all dirt and loose chips of concrete from the crack. Fill with a urethane caulking (if possible) and strike flush with the deck surface. Center a 2" (5 cm) wide piece of 66R release tape (or paper masking tape) over the crack and stick it firmly and thoroughly to the deck. Stripe coat 60 mils (1.5 mm) (1/16") of LM-60 over the tape and for 3" (8 cm) on each side of it. When applying the membrane on the main field of the deck, go over the stripe coat to achieve a total thickness of 120 mils (3 mm) (1/8").

C. Expansion Joint Covers:

1. Choose NF-621 field curing neoprene sheet in a width that will give at least 3" (8 cm) of bonding area on each side of the joint, plus enough material to loop over the backer rod. Use a chalk mark placed 3" (8 cm) on each side of the joint as a guide for applying adhesive. Allow adhesive to dry.
2. Stir N-1207 adhesive to obtain a uniform consistency. With roller or brush apply N-1207 to the deck on either side of the joint to a point just beyond the chalk marks. (This coat may be thinned on unprimed deck). Allow N-1207 to dry until it can be touched without sticking, about ½ hour. Apply a second coat of adhesive (unthinned) to the deck (not required on primed deck) and one coat to the neoprene sheet (on the side not covered with the polyethylene liner). Allow to dry.
3. Fold the neoprene sheet in half lengthwise so that the polyethylene surface is together. Place one edge of the sheet, adhesive side down, along the chalk line on one side of the joint. Place directly into position as the adhesive surfaces will bond immediately upon contact and the sheet cannot be moved. Stitch along the edge of the sheet to obtain a positive bond. Once the edge is bonded completely, work the stitcher or a flat faced steel roller toward the expansion joint to obtain 100% positive contact. End laps must be joined prior to placement of flashing since a waterproof lap cannot be formed over a backer rod.
4. Place a backer material (solvent resistant expanded plastic such as polyethylene or polypropylene) in the joint. The backer material should be oversized so it can be compressed into the joint and allowed to protrude 2" (5 cm) above the deck.
5. Unfold the neoprene sheet over the backer material and adhere it to the deck on the opposite side of the joint. Stitch the sheet from the joint outwards to the edge to obtain positive contact. Remove the polyethylene liner.
6. Apply a fillet bead of urethane caulking along all edges and lap seams of the sheet.
7. After all neoprene sheet has been in place a minimum of 24 hours, apply a tie coat of N-1207 prior to application of the LM-60 membrane which will go over the sheet.
8. After placement of protection board, a sheet metal protective cover must be installed to protect the expansion joint prior to installation of any wear course.

D. Flashing at Deck and Wall Junctures:

1. If the joint at the wall and deck juncture is non-moving, apply LM-60 at 60 mils (1.5 mm) (1/16") in a cove prior to application of the main deck. Apply an additional 60 mils (1.5 mm) (1/16") at the juncture when applying the overall membrane for a total thickness of 120 mils (3 mm).
2. If the joint at the wall and deck juncture is moving, flashing is accomplished by using field curing neoprene sheet. This is placed prior to application of the overall membrane.
   1. Choose a width of neoprene sheet sufficient to extend 4" (10 cm) onto the deck and 6" (15 cm) up the vertical wall. Roll out the sheet close to application area. Use length as long as possible to reduce the number of lap joints, but only as long as is convenient to handle.
   2. Place masking tape on the wall and a chalk line on the deck as a guide for adhesive application.
   3. Mix adhesive to obtain a uniform mixture. Apply by brush or roller to the deck ½" (1.3 cm) beyond the chalk line and to the wall onto the masking tape. This coat may be thinned on unprimed surface. Remove masking tape while adhesive is wet.
   4. When the first coat of adhesive is dry, apply a second coat (not required on pre-primed surface) of unthinned adhesive to the deck, wall and to the neoprene sheet on the side not covered by polyethylene liner.
   5. Place a 1" (3 cm) expanded plastic backer rod into the wet adhesive at the juncture of the deck and wall.
   6. When the N-1207 adhesive is dry, fold the neoprene sheet in half lengthwise so that the polyethylene surface is together. Carefully lift the neoprene sheet without stretching it and place the edge (adhesive surfaces together) along the chalk line on the deck. Stitch the edge to assure positive contact and continue with roller and stitcher toward the wall. On the wall work from the bottom to the top in the same manner. Remove the polyethylene liner. End laps must be joined prior to placement of flashing since a waterproof lap cannot be formed over a backer rod.
   7. Apply a fillet bead of urethane caulking along edges and lap seams of the sheet.
   8. After all flashing is installed, wait 24 hours then apply a tie coat of N-1207 to the horizontal surfaces of the neoprene sheet or wherever the LM-60 will be applied.
   9. When the LM-60 membrane will come into contact with a wall waterproofing system, the wall system must be installed prior to the LM-60 membrane. Overlap LM-60 a minimum of 6" (15 cm) onto the wall system. An alternative method is to use neoprene sheet as the dividing interface between the two systems.

PART 6 - APPLICATION OF LM-60

1. If any neoprene sheet is to be covered with LM-60 it must be coated with N-1207 adhesive (may be thinned 50%) to obtain a bond. Application rate is up to one gallon per 250 square feet (4.1 L / 25 m2). Allow drying ½ hour.
2. On vertical flashing details, two brush coats must be applied prior to application of LM-60H.
3. With a trowel (5/16" x 5/16" V notched trowel is effective in controlling thickness) or squeegee, spread the material over the deck at an average thickness of 1/16" (1.6 mm). Four gallons per 100 square feet (15 L/10 m2) will yield this thickness. Where LM-60 meets neoprene sheet, the LM-60 must overlap a minimum of 3" (8 cm).
4. When joining areas where there has been a delay of 48 hours or more, the older material must be solvent wiped with T-5112 to obtain a suitable bond between the old and new material. New material shall overlap the older material (by a minimum of 3" (8 cm)).

PART 7 - APPLICATION OF LM-60

LM-60V may be applied with a mason's trowel. When using a trowel, dip the mixed material from the pail with the end of the trowel and in the same motion stick to the wall. Do this three or four times, then spread the material up the wall at 1/16" (1.5 mm) average thickness. Four gallons per 100 square feet (15L/10m²) will yield this thickness. If a notched trowel is used to control the coverage, use the back edge of the trowel to level off the ridges. A second method is to pour LM-60V from the pail onto the wall in a stripe about 3" (8 cm) wide. The LM-60V is then trawled in 1/16" (1.5 cm) thickness. Work horizontally with trowel and from the top downward.

PART 8 - SPRAY APPLICATION OF LM-60

1. LM-60H may be spray applied. LM-60H generally will be thinned less than LM-60V to obtain the correct viscosity to spray properly. Note that when thinned, a greater wet film thickness than 60 mils (1.5 mm) is necessary to yield 60 mils (1.5 mm) (1/16") dry film thickness.
2. LM-60V may be spray applied. At least two passes, with a waiting period between coats, will be necessary to build up a 60 mil (1.5 mm) (1/16") dry film thickness of the membrane.

PART 9 - WATER TESTING

If a water test to check the integrity of the membrane is to be performed, allow a minimum of 48 hours cure time before doing the testing. Plug drains, flood area of membrane and leave flooded for 48 hours.

PART 10 - INSTALLATION OF PROTECTION COURSE

1. LM-60 membranes must be covered to protect against physical damage. When placing protection board, pedestals for pavers, etc., care should be taken to avoid physically damaging the installed membrane. An overall course of protection board shall be used when pedestals are to be employed as a protection against damage.
2. If no water test is to be run the protection board may be placed over the LM-60 membrane prior to complete cure while LM-60 is still tacky but cured sufficiently so as not to extrude material from beneath the protection board. Protection board may be laid loose or spot bonded with LM-60. If the ability of future access to the LM-60 membrane for inspection or repair is desired, allow LM-60 to fully cure (48 hours) prior to installing protection board.
3. Protection board shall be rigid or semi-rigid asphalt composition board (minimum 1/8" (3 mm) thick); expanded polystyrene board (minimum ½" (13 mm) thick); or 90 pound rolled roofing. Under the asphalt or asphaltic concrete paving (maximum 3/8" (10 mm) aggregate) 50 pound cap sheet or 90 pound mineral cap sheet are preferred. Two lifts of 1" (3 cm) thickness each of the paving material are recommended.
4. Protection board is not required if sand backfill to a thickness of 6" (15 cm) is used or if a thick mortar bed without wire or steel reinforcing is used.
5. If pedestals or chairs are used for pavers, rigid ¼" (6 mm) asphalt composition board shall be used.