Fabricated Steel Access Covers and Frames.

General | Single Unit Covers | Twin and multiple unit covers | Duct Run Systems | Notes

General.

1. Covers and frames are manufactured as a unit – ensure that corresponding covers and frames match and fit correctly before commencing installation.

2. The frame of an access cover must be fully supported . Any load placed onto the access cover is transferred to the structural opening via the frame. If the frame is only partially supported, the unit will not carry the load it is designed for and will ultimately fail . – please see sketches below.

3. Recessed covers (excluding paving infill) must be fully infilled with grade C25 concrete , by volume, 1 cement, 2 sand, 3 coarse aggregate ( 9.5 to 3mm), to achieve their stated loading capacity.

Single unit covers.

 1. Place empty frame ( cover and frame with hinged units ) around the chamber, centralizing it to the structural opening. Pack up the frame to the required level with suitable hard packing material, such as tile.
Care must be taken to ensure the frame does not over hang the opening.
If the frame is provided with fixing pads, these must be used to bolt the frame to the sub-floor.

2. Replace lid momentarily and ensure that no rocking occurs. Re-pack if necessary.

3. Fill the unsupported areas of the frame with suitable grouting material. The underside of the frame must be fully supported. Allow grout to fully harden.

4. Replace cover, taking care not to disturb the frame. If locking, lock down the cover but do not tighten down.
Recessed Concrete Infill Covers. 1 to 4 as above, then proceed as follows:

5. The cover can now be infilled. Care must be taken not to get debris in the lifting / locking points – ‘Denso-tape' or similar provides ideal protection. Allow the concrete to harden before continuing installation.
For block paving / slab infill products, it is acceptable to infill the lid and around the frame at the same time.
To eliminate sand seepage we would recommend that Typar SF32 is fitted within the lid recess with a 20/30mm lip to the lid sides.

6. The frame can now be back-filled. On hinged covers care must be taken not to get concrete into the hinge mechanism points – ‘Denso-tape' or similar provides ideal protection.

7. When the backfilling has hardened sufficiently, any cover locking bolts / devices can be tightened.

 Twin and multiple unit covers.

 The majority of twin and multiple unit covers are fitted with removable support beams and support pockets. Multiple leaf units will also often have intermediate beams running between the main support beams and main support beams to chamber wall face. If supplied pay particular attention to a numbered layout.

1a. Fit support pockets and support beams at the correct position.
Please contact our Nuneaton Sales office for the recommended bolt types.
It is imperative that the support pockets that cradle these beams are fitted / bolted at the correct level to provide support to the cover joins across the chamber opening.
In some instances fixing straps may be fitted to the frame these are to eliminate distortion in galvanising and damage during transportation. These fixing straps should be removed.

1b Place empty frame ( cover and frame with hinged units ) around the chamber, centralizing it to the structural opening. Pack up the frame to the required level with suitable hard packing material, such as tile. Please ensure the frame does not overhang the opening .

1c. If the frame is provided with fixing pads, these must be used to bolt the frame to the sub-floor.
On large multiple units, frame bolting points may be provided therefore the frames must be bolted together .
Ensure that the frames are true, level and square and will allow the lids to be fitted.

This is particulary important on hinged covers as it may cause mis-alignment in the hinging of the lids

Continue as points 2 to 6 on previous ‘single unit' page.

Duct Run Systems.

1. Before installation check all parts ( lids and frames ) against layout sketches where issued.
Where possible installation should start at a junction or a restricted end, thus reducing the effect of creep during installation. Locking units should be offered up to the duct with the lids locked in place. On non-locking units it is acceptable to fit the framing first using the required size lid as a spacer panel.

2. Place the frame (and cover on locking units ) around the duct structural opening, Pack up the frame to the required level with suitable hard packing material, such as tile.
Care must be taken to ensure the frame does not over hang the opening.
The frame is provided with fixing pads, these must be used to bolt the frame to the sub-floor.

3. Check that the lids do not rock in the frame. Re-pack if necessary.

4. Fill the unsupported areas of the frame with suitable grouting material. The underside of the frame must be fully supported.

5. Allow grout to fully harden.

6. Replace covers, taking care not to disturb the frame.If locking, lock down the cover but do not tighten down.

7.  Once the covers are in place, the frame can be backfilled.
Recessed Covers. 1 to 4 as above, then proceed as follows:

8.  The cover can now be infilled. Care must be taken not to get debris in the lifting / locking points – ‘Denso- tape or similar provides ideal protection.
For block paving / slab infill products , once the frame is bolted to the sub-floor it is acceptable to infill the lid and around the frame at the same time. To eliminate sand seepage on recessed block pavior types we would recommend that Typar SF32 is fitted within the lid recess with a 20/30mm lip to the lid sides. .

9.  When the backfilling has sufficiently hardened, any cover locking bolts / devices can be tightened.

Additional notes for units fitted with Gas Strut or Counterbalance assist lift devices.

To limit strain on the cover and frame, gas strut and counterbalanced units should be fitted without the relative assist devices. The devices should only be fitted once the installation of the cover and frame is complete and all backfilling has hardened.

Notes

1. Full fitting instructions supplied with a particular product range will supercede these instructions.

2. If any doubts exist about fitting, please contact our Nuneaton Sales Office.

3. Covers and frames are not designed to take traffic when not fully fitted.