Infills in modular reinstatements

A12.2.7

General

Where gaps greater than 5 mm between the nearest module and the immediately adjacent fixed feature (such as edgings, channel blocks, drainage features, surface boxes, ironware) or boundary feature (such as walls, fences and the like) arise as a direct result of works, the undertaker should avoid the gap by cutting the modules to the proper dimensions. If this is not possible, the undertaker must fill the gaps to the full depth of the adjacent paving module as follows:
1. for smaller gaps a 1:4 cement to sand mortar ratio should be used;
2. for larger gaps, where aggregate can be used, a 1:5:3 cement to sand to aggregate concrete ratio should be applied, using a maximum aggregate size of 10 mm.
3. alternatively, PMMA can be used as infill prior agreement with the authority.
Infills should generally be as small as possible. Where the physical characteristics of the bond, fixed feature, or proximity of other fixed features do not allow for a small infill, then best endeavours should be used to achieve surface tolerances (see S2) with the smallest infill possible.
Infills should match existing work by the Authority.
If the gap requiring a new cement infill is the result of an uneven surface (existing before commencement of the works), the new cement infills should be limited to a 1 year guarantee. All practicable effort should be made to avoid the use of cement infills for this application. For the 1 year guarantee to apply to the cement infills the undertaker is required to document the existing surface before commencement of works and must be able to demonstrate why all alternatives to the use of cement infills for this application have been ruled out.

A12.2.8

Infill widths and limitations

Where possible, infills should be limited to a maximum width of 50 mm in modular areas, irrespective of whether the existing footway was originally constructed in accordance with BS 7533.
In the case of modules where one side of the module is greater than 305 mm, there are instances where it is permissible to increase the width of the infill to a maximum of 150 mm to achieve a better engineered and more aesthetically pleasing reinstatement. These include instances where the intervening distance is less than 150 mm:
1. between the undertaker’s newly laid apparatus and the nearest module (on any side), or
2. between two or more pieces of undertaker’s newly laid apparatus, or
3. to an existing fixed or boundary feature.
Where it can be shown to be acceptable custom and practice, in exceptional cases the maximum permissible infill width may be increased to 200 mm for irregularly shaped apparatus. Typical examples are in NGA12.
Similarly, for modules where all sides are 305 mm or less, there are instances where it is permissible to increase the width of the infill to the same as the full width of module (measured on the shortest side) to achieve a better engineered and more aesthetically pleasing reinstatement. These include instances where the intervening distance is less than the full width of a module plus 25 mm (measured on the shortest side):
1. between the undertaker’s newly laid apparatus and the nearest module (on any side), or
2. between two or more pieces of undertaker’s newly laid apparatus, or
3. to an existing fixed or boundary feature.
Typical examples are in NGA12.

A12.2.9

Acceptable localised loss of modular pattern

Physical characteristics may prevent or limit the possibility of completing a uniform and closely matching modular reinstatement immediately adjacent to features. The physical characteristics of the module itself, the existing as-laid bond, as well as the physical characteristics of the fixed or boundary feature, may individually or collectively contribute to such a situation.
In all instances, the undertaker should attempt to minimise the width of the infill. However, the following exceptions are permissible:
1. Where the above physical characteristics are present, permanently reinstated modules immediately adjacent to the feature may be laid with a degree of localised loss of bond pattern. The introduction of a stringer (or in some cases, soldier) course immediately adjacent to the feature is not considered as a loss of bond pattern. The loss of bond pattern should be limited, where practicable, to the first two rows beyond any stringer course, being laid in such a manner as to aesthetically integrate with the surrounded bond pattern. Typical examples are indicated in NGA12.
2. If adjacent modules abut an existing contiguous infill such as at a property boundary, then the infill must match the existing.
3. In the case of fixed features that are not rectangular, there is no requirement to cut modules to match the edge profile of the fixed feature to otherwise reduce the infill at irregular edges.
4. Where localised custom and practice adopted by the authority for its own works differs from the above, infills may be laid to a standard consistent with that of the authority.