Dur-Red Roof Hatch Guide: RHUVA Dome Hatch, RSRWB Rail and LP-4 Post

The Dur-Red products we carry make up one complete roof access point: the RHUVA dome ladder hatch for a 30 x 36 inch opening, the RSRWB safety railing with self-closing gate that bolts to that hatch, and the LP-4 ladder safety post that gives the climber a handhold at the top of the ladder. This guide covers what each part is, how the three fit together, and what to confirm before you order.

The RHUVA dome ladder hatch

A standard roof hatch has a solid metal cover. The RHUVA cover carries a polycarbonate dome, so the hatch lets daylight into the ladder well. Our listing describes a 30 x 36 inch dome ladder hatch with an aluminum self-flashing frame, double clear over white polycarbonate domes, 1 inch insulation, a mill finish, railing ready construction and an exit on the length. The Dur-Red data sheet lists this size as the RHUVA-1, 36 x 30 inches in width by length, where the length is the hinged side.

The Dur-Red specification says the RHUVA door opens 88 degrees. OSHA 1910.23(d)(9) requires a counterbalanced hatch at the top of a fixed ladder to open at least 70 degrees from horizontal and to give easy access to and from the ladder. Dur-Red describes the dome hatch as opening and closing with one hand, and its data sheet says to order by the curb opening.

Installing the hatch

• The roof opening equals the hatch size, measured inside curb to inside curb.
• Over a fixed ladder, put the hinged side opposite the ladder, at the climber's back. Over a stair, put the hold-open arm at the head of the stair.
• On pitched roofs up to 7:12, run the hinge side parallel to the slope.
• Fasten the flange through the 0.19 inch holes provided. Dur-Red recommends #10 screws into a wood frame and drilling larger holes for larger bolts.
• The cover is spring loaded and ships with steel safety bands. Remove them only after the hatch is installed.

For maintenance, Dur-Red calls for operating the hatch by hand once a year and cleaning a domed cover with mild soap and water, never abrasive cleaners.

The RSRWB hatch railing

Dur-Red's RSRWB railing bolts to the curb capflashing, so it does not penetrate the roofing membrane. The RSRWB-1L-GATE is the ladder model, sized for a 36 x 30 hatch with the gate on the length. That matches the RHUVA, which is railing ready and exits on the length.

The drawing requires a Railing Ready hatch with pre-drilled holes in the capflashing, and it states that the curb flashing must not be penetrated. Our listing notes that this railing comes only in galvanized mill finish, not aluminum. Dur-Red states that the railing complies with OSHA 1910.29 when it is installed with the self-closing gate, and it recommends checking with the local authority having jurisdiction because interpretations of OSHA and building codes vary.

That gate matters. Under OSHA 1910.29(b)(13), a guardrail around a hole used as a point of access, such as a ladderway, must have either a self-closing gate that swings or slides away from the hole or an offset opening. OSHA 1910.29(b)(1) sets the top rail at 42 inches, plus or minus 3 inches.

The LP-4 ladder safety post

The LP-4 is a preassembled steel post in safety yellow powder coat that clamps to the top two rungs of a fixed ladder. A counterbalance spring lets the climber raise it with one hand while keeping three points of contact. The Dur-Red guide says that when fully extended the post stands 42 inches above the landing. To lower it, lift the locking plate and push the post down.

• Fits round or square rungs from 3/4 to 1-1/4 inches, spaced 12 inches apart.
• Mounts centered, on the inside of the ladder, opposite the climbing side, with two U bolts, washers and locknuts. It ships with U bolts for both small and large rungs.
• The drawing shows a 1-1/2 x 1-1/2 x 1/8 inch tube, 60 inches long. The post weighs 25 pounds.
• Once the post is mounted, the rung centers must still have at least 7 inches of foot clearance. OSHA 1910.23(d)(2) sets that same 7 inch minimum behind a fixed ladder.

OSHA 1910.23(d) says ladder side rails on through ladders and grab bars must extend 42 inches above the access level or landing. Dur-Red states that the post meets ANSI A14.3 and OSHA requirements.

Warranty

The Dur-Red warranty certificate posted with the hatch covers roof hatches and roof accessories for five years from the date of shipment against defects in materials and workmanship. It refers to a separate warranty for safety railings.

FAQ

Why choose a dome hatch over a solid cover?

The polycarbonate dome lets daylight down the ladder well, so the hatch doubles as a small skylight.

Will the RSRWB railing fit a hatch from another manufacturer?

The RSRWB drawing calls for a Railing Ready hatch with pre-drilled capflashing. Send us the hatch make, the inside dimensions and a photo of the curb so we can confirm the fit before ordering.

Which side does the gate go on?

For ladder access, Dur-Red puts the gate exit on the length. For stair access, it goes on the width.

Next steps

All three products are on our Dur-Red brand page, and hatch and ladder drawings from every manufacturer we carry are on the roof hatch and ladder spec sheets page. For background on the fall protection rules, see OSHA fall protection for skylights. To get a quote on the hatch, railing and post together, send the opening size, exit direction and ladder rung size through the ladder and hatch request for quote page.