Heavy Duty Epoxy Mortar Systems

Introduction
TPM Systems incorporate epoxy resin with select, size-graded aggregates to form a trowel applied floor topping for demanding applications where maximum strength and protection are necessary. TPM Systems have a high aggregate to resin ratio, which requires the installer to provide the energy to spread and finish the material to the specified thickness. Each General Polymers mortar system has a specific resin and aggregate combination. Refer to the General Polymers System Bulletins for the products required on your application. For each system you will find all the components, coverage rates and typical batch quantities.

Inspection & Surface Preparation
Read General Polymers "Instructions for Surface Preparation" (form G-1) for complete details on preparing the concrete surface prior to installation. These materials are mortars and are typically specified at 1/4", which means they will hide surface irregularities, unlike a self-leveling system.

Every job should be inspected for certain conditions prior to installation. Check for adequate power, lighting, heat and ventilation. Other than TPM 126(low temperature) these systems should not be installed with a substrate temperature less than 50F. Best results are achieved between 65-80F.

Priming
By definition mortars contain significantly more aggregate than resin (4 or 5 to 1). This means the aggregate rich mortar will not be 100% in contact with the substrate. Select a primer that leaves enough film to enhance contact points, but do not puddle the primer. A high or 100% solids primer is preferred. For best results apply the mortar into a tacky primer, solvent-based, or wet/tacky if 100% solids. If the primer will cure (dry) prior to application of the mortar, broadcast a large grit sand (20-30 mesh) into the wet primer to provide a mechanical tooth.

Mixing the Mortar
Aggregate rich mortars are best mixed in a unit designed for this purpose. A Kol (bucket) or mortar mixer is preferred depending upon the size of the installation. A drill and paddle should only be used for small mixes.

A Kol (bucket) mixer will only handle 1/2" the typical batch quantity on the System Bulletin. A mortar mixer can handle 3 or 4 Typical Batch Quantities. Use a paddle type mortar mixer, the tumbler type will not wet the aggregate evenly. Match the mixer to the installation and crew size.

The epoxy binder resin should be premixed in a separate container, with a drill and paddle. Then added to the mortar mixer prior to addition of the aggregate. Mortar mixers are not efficient in either agitation or rpm's to fully combine the resin components. Mix until the aggregate is fully wet out prior to placement. You can dump the material on the floor directly from the bucket you used to mix with when using a bucket mixer. A mortar mixer will require a wheelbarrow to transport the material from the mix station.

Aggregate Blends/Ratio
Aggregate purchased from General Polymers has been specifically designed in combination with the proper General Polymers resin to provide a workable, dense and well-compacted topping. Substitution of another aggregate blend may change workability, finish and performance properties.

Temperature and environmental conditions can and will affect workability of the material. The General Polymers suggested batch quantities (aggregate to resin) can be adjusted slightly, plus or minus 5 lbs., to improve placement and finish. Any change will impact the amount of grout and or seal coat materials.

Mortar Placement
The mixed mortar should be placed and spread on the floor immediately after mixing. Material left in mass can result in a reduction of working time, resin draining away from the aggregate and inconsistent finish properties. The mixed mortar will require the use of a screed box, screed/gauge rake or trowel to evenly spread the material. The mortar is then compacted/closed via use of a hand or power trowel. The initial screeding of the mortar is typically 1.5-2.0 times thicker than specified thickness to allow for compaction and closing. This is dependent upon the equipment used, system and temperature. The first few mixes will be used to determine the proper screed height to arrive at the specified thickness and finish. Do not mix more material than can be applied and finished within 30 minutes.

The use of a screed box and power trowel will result in a more consistent application; compaction, flatness and finish are all made more uniform. Imperfections in the troweled mortar will be highlighted when the floor is grouted and sealed. The mortar has little gloss and imperfections can be difficult to see. Good lighting is important. Once the mortar has cured trowel marks, humps, etc. can only be removed via grinding. For hand trowel applications a halogen work light, shined horizontally across the floor during application, will identify imperfections that can be addressed. Grinding an entire epoxy mortar is a slow and expensive process, so placement is important. It is, however, practical and prudent to use a floor grinder to remove random trowel marks and high spots especially if the floor is to receive a color quartz topping (TPM #115-U1).

Grouting
This process has one or two functions dependent upon the System specified. In standard, solid color Systems the grout is used to fill the porosity inherent in an aggregate rich mortar system. In the Upgraded Systems (U Series) it is also acts as the binder for an excess broadcast of silica sand or color quartz. One or two grout coats will be required, dependent upon the size of the broadcast aggregate and non-skid texture desired.

Standard Series: The specified grout material is mixed, as directed on the System Bulletin, and applied via a spring steel trowel or rubber squeegee and back roll to remove lines. Coverage is directly impacted by the thickness and density of the mortar, use 100-120 sq. feet per gallon as a guide. It is typical to have areas of the floor absorb more than others. An alternate method, which provides good results, but requires more labor, is as follows. Apply an even film over an expanse of floor and allow to stand for 10-15 minutes. Walk back into the wet material and pull the material as tightly as possible. This will force more material where needed and pull any excess material onto the next area to be covered. If done properly no back rolling is required. Less material will be used with this method.

Upgraded Series: Dependent upon the System specified the grout material would be clear (TPM#115U1) or pigmented (U3&4). Mix per the instructions on the Technical Data Sheet of the product. Apply via spring steel trowel or squeegee at a rate of 100-120 feet per gallon and back roll. When the material has leveled, no longer than 30 minutes, broadcast color quartz (U1) or silica sand (U3&4) until complete refusal, no resin or wet spots visible. The aggregate should be broadcast up, into the air to allow it to spread and fall gently into the wet coating. Care should be taken not to step in resin, which has received any aggregate. The aggregate will not allow the resin to flow back and fill the depression. General Polymers supplies 40-60-mesh silica sand for broadcasting. If you provide your own sand the amount required and seal coat coverage may be altered.

Seal Coat
General Polymers offers a variety of seal coat options; urethane, epoxy, gloss, satin, solvent-based, 100% solids, stipple or smooth finish. There are too many to discuss individually, refer to the Technical Data Sheet for the specified product.

Standard Series: Inspect the floor for any imperfections that may require patching. For best results lightly sand the surface with a floor machine and tack wipe prior to application of the seal coat. Always apply 100% solids epoxy seal coats via a squeegee and back roll. Typical coverage is 200 square feet per gallon on a well-grouted mortar floor.

Upgraded Series: Prior to application of the seal coat all loose aggregate must be removed. To achieve a smoother finish the surface can be lightly sanded with a floor machine. For best results removal should be followed by a vacuum pick up. Excess broadcast floors provide a uniform non-skid but will require significantly more seal coat material. Typical coverage for a 100% solids epoxy is 100-120 feet per gallon.