Manhole cover with Clicklift installation guide

In order to maximise the performance of the installation, ensure the following guidance is followed:

• The Clear Area of the new frame is the same or larger than that of the chamber opening.
• The whole of the frame flange will be fully supported by the chamber top construction.
• No part of the ironwork cover elements will foul on the chamber top when they are placed back in the frame.
• The chamber top is; dry, dust & debris-free and in good condition (repair where necessary, ideally using bedding mortar to reinstate any brick courses) and ready to receive the bedding mortar.
• The top of the chamber is sufficiently textured (rough) to provide a ‘key’ with the intended bedding mortar.

Based on the anticipated construction phase / finished surfacing level and taking account of the nature of ClickLift assembly options (main frame depth and frame raising section depth), calculate the ironwork’s mortar bedding depth requirements using the following as a guide:

• ≥85mm = Sufficient for another full or partial course of engineering bricks or proprietary chamber shaft section(s), prior to bedding mortar application.
• 35-84mm = Sufficient for UniPak adjusting units & mortar OR UniPak mortar only.
• 10-34mm = Sufficient for UniPak mortar only.

N.B.1: Ensure that the under-frame mortar bedding depth will exceed 10mm at all locations.

N.B.2: Ensure sufficient volume of mortar is available to complete the bedding and achieve the required bedding thickness and a 10mm enveloping of the frame flange surface. As a guide, a typical 1x25Kg tub of bedding material will provide up to 15mm bedding depth for a typical 600x600mm Clear Area access cover.

This procedure assumes that the bedding mortar used is for permanent fixing of the ClickLift main frame in readiness for later fitment of the ClickLift raising section.

Frame Tamping is the expected common method of ironwork Frame alignment with the anticipated (or existing) surrounding road surface and in order to ensure its effectiveness, particular attention is drawn to the following:

• If it is anticipated that the temporary bedding mortar’s Working Time will be short, ensure all installation preparations are completed prior to any mixing of the bedding mortar.
• Strictly follow the instructions on the bedding mortar packaging.
• Always sandwich any bedding ‘adjustment units’ used between layers of at least 10mm-thick bedding mortar.

• Ensure the as-laid bedding mortar exceeds the frame flange perimeter area by a minimum of 50mm.
• Ensure the as-laid bedding mortar bed thickness is c.20mm greater than the required finished bedding thickness in order to allow for a depth reduction during frame Tamping operations.
• Place the frame on the mortar centrally over the chamber opening and fill any remaining under-frame gaps with bedding mortar, taking care to avoid dropping excess or loose mortar into the chamber. Then ‘Tamp’ the ironwork frame into it to achieve the required frame level, at the same time ensuring compaction of the underlying bedding mortar. (see paragraph 4, below, for alternative methods of frame levelling due to short mortar Working Times).
• Ensure the ClickLift main frame level is within 5mm of the construction-phase road surface level (so that the ClickLift raising section is the same as the finished surfacing depth).
• Apply additional bedding mortar mix to envelope the frame flange to a minimum depth of 10mm.
• Compact any remaining laid mortar not already compacted during the frame Tamping operation and then texture its surface (e.g. with a stiff-bristle brush) where it will be in later contact with other backfill or surfacing materials.
• Only smooth bedding mortar that will be visible after completion of the whole reinstatement installation.
• Only apply any backfill or surfacing repairs when the bedding mortar has fully cured, as evidenced by a successful ‘hammer-test’ (no indentation from light hammer blows).

^{(for use at elevated temperatures where short mortar working time prevents conventional frame tamping)}

Where the bedding mortar working time is too short to allow mortar placement and frame alignment using a conventional ‘tamping’ technique, alternative installation techniques may be used to effect frame alignment.

Examples of alternative techniques include: UniForm Wedges or ScrewLift adjustment accessories, where these may be used to effect frame-levelling in lieu of frame tamping. Either method may be used, followed by application of a Wrekin-approved flowable bedding mortar (which will require a temporary dam to be formed around the chamber top) or manual application of UniPak mortar under and over the frame flange (enveloping).

Where manual enveloping of the frame is carried out (achieving 10mm minimum depth underneath and on top of the flange), ensure that all of the applied mortar is compacted and its resulting surface is textured to provide a key to subsequent reinstatement materials.

N.B.3: Where UniForm Wedges or ScrewLift accessories are employed for frame levelling, they may to be left in-situ with the surrounding bedding mortar.

If frame fixing anchors are to be used in conjunction with a bedding mortar as a means of additional frame retention to the chamber top, drilling or hole-forming to receive anchors should only occur when the bedding mortar has fully cured.

N.B.4: Ensure any chamber fixing location and anchor type is appropriate for the expected loads.

N.B.5: Anchor fasteners are not supplied with Wrekin Products’ ironwork, as standard.

When the Clicklift main frame installation has been completed and its bedding materials have cured. The construction-phase surfacing may be applied, which should align flush (within +/-5mm) with the top of the ironwork in order to deter damage by construction traffic.

N.B.6: It is vital that when applying any surfacing courses, the ironwork is not disturbed or impacted, particularly where mechanical compaction equipment is employed, as this can damage the newly-laid bedding materials.

Care should also be taken to remove all surfacing aggregates from the surface of the manhole cover and frame before compacting/rolling the asphalt in order to prevent any likelihood of point loading from compaction equipment.

In situations where the construction-phase installation is likely to become exposed to pre-service (construction-site) or other damaging traffic types, ensure that it is protected until its normal service use, by temporary employment of the following;

• Conventional Road Plates
• Wrekin Armadillo protector shell ironwork protection devices.

N.B.7: Trafficking of the installation must not occur until all reinstatement and surfacing materials have fully cured and any necessary protection is in place.

N.B.8: Fitment of the ironwork flush with the surrounding road or pavement affords it some protection from construction traffic but may not prevent damage from the high point loads associated with these traffic types. Hence, consider the additional protection shown above.

Immediately prior to application of the finish surfacing and where the in-situ ClickLift main frame is required to be raised to finish levels, the following procedure and guidance should be followed:

• Read Wrekin’s ‘ClickLift Do’s & Don’ts’ document on the website
• Using BS7903 lifting-key-profiled apparatus or BS7903 long-shank lifting keys, remove the covers from the in-situ frame and place to one side for later refitment.
• Clear any debris away from the top edge and cover contact points of the in-situ ClickLift main frame.
• Select the appropriate* ClickLift raising component (Clear Opening and raising height needed) for the intended wearing course depth.
• Place the ClickLift raising component into the in-situ frame (and observing the one-way-fit is maintained) and gently tamp it with a rubber-faced mallet evenly around its perimeter into the frame until the 4nr internal corners of the ClickLift raising component contact** the seats on the frame.
• Re-introduce the covers back into the finished ClickLift frame.
• Apply a proprietary bitumen-based cold-joint sealer to the visible outside faces of the [now in-situ] ClickLift raising component. E.g. Larsen BES10 or similar.

**N.B.9: As the ClickLift raising component requires some engagement with the outside top edge of the ironwork frame, it may be necessary to clear away surrounding surfacing coincident with the top edge of the frame in order for the ClickLift to fully contact its frame seats and activate its barbed retention ‘legs’.

N.B.10: Ensure that the correct ClickLift raising component height (from the range of 30, 40, 50 & 60mm) is selected before fitting to the in-situ frame, as once fitted, it cannot be easily removed.

N.B.11: The application of a cold joint sealer to the ClickLift vertical external face is particularly important if it’s located in a concrete surround, for thermal expansion reasons.

With the Clicklift ironwork now fully assembled and installed, the finish surfacing may be applied, taking care that the ironwork is not disturbed or impacted, particularly where mechanical compaction equipment is employed, as this can damage the ironwork and/or bedding materials.

Care should be taken to remove all surfacing aggregates from the surface of the ClickLift frame before compacting/rolling the asphalt in order to prevent any likelihood of point loading from compaction equipment.

In situations where the finished installation is likely to become exposed to pre-service (construction site) or other damaging traffic types, ensure that it is protected until its normal service use by the temporary employment of one of the following;

• Conventional Road Plates
• Wrekin Armadillo ironwork protection devices.

N.B.12: Trafficking of the finished installation must not occur until the surfacing has fully cured and any necessary protection is in place.

In general, non-hinged ironwork products require little routine maintenance during their lifetime when exposed to their normal UK service environment, other than ensuring any lifting keyways are clear and, where desired, repainting of their trafficked surfaces.

Exceptions to this include ironwork assemblies that incorporate; perishable, replaceable components. E.g. Seating gaskets in circular covers.

It is, however, always good practice to clean the contact (seating) positions of covers and frames when access has been gained to their underlying chambers.

For specific guidance on assessment of an installation’s condition, refer to the WRc Inspector’s Guide to Street Ironwork for the UK Water Industry CP373a/P8669.

N.B.13: In order to deter debris ingress into manhole cover lifting keyways (and to ensure Lifting Key fitment), Wrekin’s GritBlocker accessory may be used as a permanent fitment into same.