Trench Castings: Installation Instructions

Below are suggested forming procedures for non-bolted, bolted and self-forming Neenah trench castings.

Suggested Forming Procedures for R-4990 and R-4999 Series With Type X Frame+

Suggested Forming Procedures

for R-4990 and R-4999 Series With Type X Frame

For those who are not experienced in the installation of Neenah drainage structures (R-4990 or R-4999 Series), the following procedures are one method of achieving desirable results. Forming Procedures, Non-Bolted Units

Materials

Under normal situations, use 3/4 inch plywood for forming walls. 2x4's are suitable for studs, plates, bracing and spreaders. A typical installation is shown in Figure 1a. Details and suggestions are based on using the Neenah Foundry Type "X" frame.

Pour the trench bottom to the proper depth and slope and allow curing time. Construct the forms. For properly fitting covers, the forms must be PLUMB, STRAIGHT, LEVEL and SOLID. The width of the forms (see Figure 1b) establishes the trench wall. This dimension must correspond with the "C" dimension on Figure 1a. The top of the form (see Figure 1b) corresponds to the final grade elevation when installing non-bolted frame and grates/lids. Spreaders are installed, extending them beyond the edge of the form, to provide a stop for the wood seatforms (see Figure 2 and 3).

Cut the wood seat forms to the exact inside horizontal and vertical dimension of the iron frame seat (Note: all Neenah frames have a slight radius at the corner of the seat and vertical face of the iron frame sections so the wood seat form pieces should be beveled to accommodate this radius). The wood seat form is nailed flush to the top of the form walls, and the iron frame pieces are nailed to the wood seat forms through the holes provided in the side wall of the iron frame sections. In proper orientation, the anchor lugs on the iron frame pieces are positioned downward. Iron frame sections should be butted together snuggly, leaving as little gap as possible. The iron frame seat form and plywood sides of the form are then secured with 9 gauge tie wire tied through a drilled hole in the plywood side wall (see Figure 3). Number 3 rebar can be installed through the anchor holes provided on the iron frames.

Check measurements. The grate/lid opening dimension must correspond to the "A" dimension plus 3/16" maximum per side (see Figure 1a and 3).

Pour concrete using the top edge of the iron frame pieces as a final elevation guide. Strip forms after concrete is properly cured. Install grates/lids. The completed installation should resemble Figure 1a.

Forming Procedures, Bolted Trench

Materials

Under normal situations, use 3/4 inch plywood for forming walls. 2x4's are suitable for studs, plates, bracing and spreaders. A typical installation is shown in Figure 1a. Details and suggestions are based on using the Neenah Foundry Type "X" frame.

Bolted frames and grates/lids are furnished assembled (see Figure 4a), and therefore require appropriate forming procedures. AT NO TIME SHOULD THE UNITS BE DISASSEMBLED DURING INSTALLATION! VERIFY THAT THE 3/16" PER SIDE MAXIMUM GAP BETWEEN FRAME AND LID HAS NOT CHANGED DURING TRANSPORT. WHEN SATISFIED THE GAP IS CORRECT, TORQUE BOLTS TO ASSURE THE PIECES REMAIN IN THAT ORIENTATION.

Pour the trench bottom to the proper depth and slope and allow curing time. Construct the forms per Figure 4a. For properly fitting covers, the forms must be PLUMB, STRAIGHT, LEVEL and SOLID. The width of the forms establishes the trench wall. This dimension must correspond with the "C" dimension on Figure 1a.

Construct the forms (see Figure 4a). The grate/lid top surface establishes the final grade elevation when the assembled iron casting unit is set on the form (See Figure 4b). Accordingly, form side wall elevation is set at final grade elevation less the seat depth "B" dimension (Note: "B" dimensions vary per catalog number. Neenah recommends checking dimensions on the catalog line item of page 266. If unsure, contact product engineering or your Neenah representative.).

Set frame and grate/lid assembled sections on the forms, taking care to keep the sections tight to one another to eliminate creep. When the sections are in the proper position, wire them to the bracing as show (see Figure 5). Number 3 rebar can be installed through the anchor holes provided on the iron frames.

Check measurements. The grate/lid opening dimension must correspond to the "A" dimension plus 3/16" maximum per side (see Figure 1a).

Pour concrete using the top edge of the iron frame pieces as a final elevation guide. When concrete is properly cured, unbolt and remove grates/lids, retaining their position and orientation. GRATES/LIDS MUST BE REINSTALLED IN THE EXACT WAY THEY CAME OUT TO ASSURE PROPER BOLTHOLE ALIGNMENT. DO NOT ALLOW DEBRIS TO FALL INTO THE FRAME BOLTHOLES AS IT MAY PROHIBIT PROPER TIGHTENING OF BOLTS. Strip forms and replace grates/lids in the same location and orientation as they came out. Reinstall bolts, tightening them to the specifiers desired torque. The completed installation should resemble Figure 1a.

General Comments for Non-bolted and Bolted Applications

All frame sections are manufactured and furnished in standard lengths. It is the responsibility of the installer to cut frame pieces to the proper length and miter corners where applicable. In cases where trench direction must change, special drawings can be furnished by our Product Engineering Department. These prints will show special lengths and cuts of grates/lids and other essential information.

Forming Procedures R-4993 & R-4994 Bolted Trench Series+

Forming Procedures

R-4993 & R-4994 Bolted Trench Series

Bolted frames and grates/lids are furnished assembled, and therefore require different forming procedures than unbolted trenches. AT NO TIME SHOULD THE UNITS BE DISASSEMBLED DURING INSTALLATION! VERIFY THAT THE 3/16" PER SIDE MAXIMUM GAP BETWEEN FRAME AND LID HAS NOT CHANGED DURING TRANSPORT. WHEN SATISFIED THE GAP IS CORRECT, TORQUE BOLTS TO ASSURE THE PIECES REMAIN IN THAT ORIENTATION.

R-4993 Forming Procedures

Follow forming procedures for bolted trench. The following exceptions apply:

  • Use Figure 6 as a guide.
  • Frame pieces can be bolted together making sure that bolts are only finger tight.
  • Reinforcing bar can be installed per Figure 6.

R-4994 Forming Procedures

Follow forming procedures for bolted trench. The following exceptions apply:

  • Use Figure 7 as a guide.
  • The frame seat for the R-4994 series cantilevers over the trench opening. This requires the distance between sidewalls to be set accordingly. In this case, bolted assemblies are set upon the sidewall forms with the contact area being the top of the form and the underside of the cantilever seat (see Figure 6).
  • The inside distance between concrete sidewalls correspond with the CS dimension shown on page 268 of the catalog.
  • Frame pieces can be bolted together making sure that bolts are only finger tight.
  • Reinforcing bar can be installed per Figure 7.

Forming Procedures – R-4996 Series Self-forming Trench+

Forming Procedures

R-4996 Series Self-forming Trench

Assumes existing slabs are at final elevation on either side of the excavation.

Materials

Under normal situations, use 2 x 4's and 18-inch lengths of fi inch all-thread rod with 2 nuts and 1 washer per cross bar support (2 cross bar supports per frame section).

Excavate trench to appropriate depth per design engineers specification. That depth must be the total of the "A" dimension and the "D" dimension plus the depth of additional masonry material specified (see Figure 7 and Figure 8a).

Attach installation materials onto frame sections (2 cross bar supports per section).

Cut 2" x 4" lengths 8 inches to 10 inches longer than the "A" dimension shown in the table above. Drill a hole in the center of each 2" x 4" length. Insert all-thread rod through hole in the bottom of the trench pan and twist on a keeper nut being careful that the threads are not exposed past the bottom of the nut. Slide 2 x 4 section over all-thread rod and tighten snuggly. Set trench pan sections into the excavation making sure the trench pans are set at proper elevation and that pan sections are mated tight together (see Figure 8b).

Pour 1st lift of concrete to sufficient depth to hold trench pan sections into position and allow to harden (see Figure 8c).

Remove assembly materials to be reused to set additional trench.

Pour second lift of concrete to final grade (See Figure 8d).

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Trench Castings

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