LFM has been building quality fiberglass reinforced manholes since 1982. We utilize the latest filament winding equipment, providing our customers with the highest quality fiberglass products in the market today. LFM fiberglass manholes are leak-free and inherently corrosion resistant to provide the lowest life-cycle cost for your next project.

Manholes are readily available for depths in excess of 50-feet and diameters up to 15.5-feet. Each manhole is designed to meet the structural requirements for the burial conditions specified. A wide variety of fiberglass manhole designs and accessories are available, for both new construction and manhole rehabilitation, to meet the specific needs of your project.

Headquartered in Giddings, Texas, LFM maintains production facilities across the United States to provide timely service to customers nationwide. No matter what water or wastewater challenge you face, LFM can guide you through the entire scope of your project. From CADD services for custom applications through technical support, budgetary estimates, mold fabrication, transportation, and field service after delivery, we are here to serve you.

ASTM Certified

Our fiberglass manholes are built to meet the rigid requirements of ASTM Standard D3753. LFM strives to supply its customers with the highest quality fiberglass structures available on the market today by meeting and exceeding all applicable ASTM requirements.

Closed-Bottom Fiberglass Manholes

LFM’s closed-bottom manholes appear similar to a conventional manhole configuration. These manholes have an integral FRP base plate to prevent infiltration of ground water. Typically, closed-bottom manholes include an FRP bench and invert. Pipe connections for closed-bottom manholes include pipe stub-outs, Kor-N-Seal® boots, and Inserta Tee® connections. When groundwater is present, closed-bottom manholes require external concrete ballast to prevent buoyancy. LFM offers precast concrete ballast slabs upon request.

Open-Bottom Fiberglass Manholes

Our open-bottom manholes are constructed without a bottom and rely on a poured-in-place concrete bottom, bench, and invert. Most open-bottom manholes are provided in two configurations; either with pre-installed pipe stub-out connections or a plain-end, square-cut bottom for a “dog house” style installation. Where a “dog house” type of installation is preferred, the installer cuts the bottom edge of the manhole’s sidewall to meet the required profile to fit over the sewer pipe.

Tee-Base Fiberglass Manholes

Our tee-base manholes are constructed as a two-piece manhole consisting of a tee-base fitting and a manhole riser. The tee-base is constructed of the same material as the adjacent sewer pipe and is installed as an in-line tee. The branch outlet of the tee is positioned upward to provide internal pipe access from the riser. The riser is, then, lowered onto the tee to create a complete manhole. Typically, a pipe coupling is built into the bottom of the riser to provide for a watertight seal against the tee-base. The tee-base fitting requires concrete encasement in order to prevent buoyancy and provide rigid side support for the tee. The concrete encasement extends above the tee and around the bottom 4-inches (min) of the riser.

Fiberglass Manhole Inserts

Also referred to as manhole liners, manhole inserts provide a structural repair to manholes that have experienced deterioration due to biogenic corrosion or aggressive industrial environments. These inserts are designed to fit inside deteriorated manholes. Diameters of the manhole inserts are sized 6-inches smaller than the host manhole’s inside diameter resulting in a 2.5-inch annulus. Installations typically involve removing the cone section of the host manhole and lowering the manhole insert until it comes to rest on the bench of the host manhole. Prior to installing the manhole insert, the installer cuts the insert to the proper length and to accommodate all pipe penetrations. After insertion, the manhole insert is grouted into place. The portion of the manhole insert that extends above the host manhole riser is, then, backfilled with suitable granular material. The manhole is then brought to grade using grade adjustment rings and a frame & cover casting. Manhole inserts are designed to withstand all structural loads (i.e., soil, hydrostatic, AASHTO H-20 traffic) without consideration of any residual strength remaining in the host manhole.

Fiberglass Metering Manholes

LFM provides metering manholes in a variety of configurations to accommodate both open-channel and closed-channel meters. For closed-channel meters, ANSI flanges are sized and spaced to meet the requirements of flanged meters. For open-channel metering, integral weirs and flumes, such as Parshall, Palmer-Bowlus and cut-throat flumes, are available. To meet specific configuration requirements, a variety of accessories such as end adapters, flow conditioning channels, stilling wells, staff gauges, hinged dome lids, hatches, ladders, grating, mounting brackets and utility taps can be accommodated.

Manhole Accessories

We also provide a variety of manhole accessories to customize new manholes and retrofit existing manholes. These include pedestrian-rated fiberglass frames & covers, RainGuard® inflow preventers, lateral inlet hubs, vents, and maintenance & inspection ports.

Professional Delivery

LFM has its own fleet of delivery trucks specifically equipped to transport fiberglass manholes and wetwells. This helps to lower delivery costs considerably. We also employ a professional delivery staff whose primary goal is to provide safe and courteous on-time delivery of our products to our valued customers. Our fiberglass structures are much lighter than a concrete equivalent, making them more affordable to deliver and much easier to handle during loading, unloading, and installation.