Whatling Construction & Similarities with Laing Easiform
BISF House member SugarRay recently asked the following question:
Hi, Can some explain the differences between the Laing Easiform 3 (i.e. post 1945) construction method and the Whatling construction method please? To me they look pretty much identical.
Hello SugarRay, thank you for your question.
In some instances the Whatling built houses appear to be remarkably similar to Easiform houses as both properties can have similar window and door configurations and external walls finished in pebbledash render.
Structurally both construction types were built using reinforced concrete as the primary construction material which is evident in the external walls of both properties. One major difference between these two different house manufacturers lies in the type of concrete used during construction. Easiform used a light weight form of Clinker Concrete in their builds, whilst Whatling Ltd preferred to use a heavier form of Dense Aggregate Concrete for their constructions
There are a number of other primary design and structural variations between these two totally different manufacturers which can be compared in the table below.
I’ve included both the Easiform types I & II for a better comparison and added a cross sectional diagrams too which you may find useful.
Concrete types
Clinker concrete is lighter than dense aggregate concrete. Clinker was a by product of industrial waste and is a rough and sometimes stony like residue derived from burnt coal or a by-product from furnaces and kilns. This type of concrete rarely required the addition of fines, such as sand or fine gravel.
Dense aggregate generally contains sand cement and aggregates.
| Easiform Type I | Easiform Type II | Whatling | ||||
|---|---|---|---|---|---|---|
| Substructure | Concrete strip footings. Damp proof course. Weep holes | Concrete strip footings. Damp proof course. Weep holes | Concrete strip foundations & under building. Damp proof course. Weep holes |
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| External Walls | Rendered [3] solid external walls of 8" clinker aggregate concrete [4] Timber wall plate [5] | Rendered [3] 3" or 3.5" dense RC [4], 2" cavity, 3" to 3.5" clinker RC [5]. Wall ties [6]. Four horizontal bands of MS reinforcement [7]. Expanded metal lathing [8]. Timber wall plate [9]. | Rendered pebbledash [3] Dense aggregate RC cavity walls [4] with leaves tied with galvanised wall ties [5] 3" cavity. Horizontal 1/2" bar reinforcement [6] lapped at corners. DPC [7] at first floor level and at eaves level. Air bricks [8]. PRC window & door surrounds [9]. Brick external window sill [10] Tiled internal sill [11]. Timber wall plate [12]. |
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| Separating Wall | Clinker concrete. | Clinker concrete cavity. | Dense aggregate concrete. | |||
| Partitions | Ground floor of clinker concrete. Upper floors, breeze block. | Ground floor of clinker concrete. Upper floors, breeze block. | Dense aggregate concrete. | |||
| Ground floor | Clinker concrete. | Clinker concrete. | Dense aggregate concrete. | |||
| Upper Floor | T&G boarding on timber joists. | T&G boarding on timber joists. | Timber boarding on timber joists. |
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| Ceilings | Plasterboard. | Plasterboard. | Presumed Plasterboard. |
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| Roof | Timber rafters, purlins and concrete tiles. | Timber rafters, purlins and concrete tiles. | Timber rafters and concrete tiles. | |||
| Variations | Mid-1920s to 1945 External walls of dense RC, cavity, clinker aggregate concrete. Separating wall of 8" clinker concrete. Clinker aggregate concrete partitions throughout. Post 1945 External walls partially clad with tile hanging on timber battens. Brick external leaf. Inner leaf of external walls of Lytag. Polythene cavity flashing above ground floor openings. Galvanised metal straps to sides of floor joists. | Mid-1920s to 1945 External walls of dense RC, cavity, clinker aggregate concrete. Separating wall of 8" clinker concrete. Clinker aggregate concrete partitions throughout. Post 1945 External walls partially clad with tile hanging on timber battens. Brick external leaf. Inner leaf of external walls of Lytag. Polythene cavity flashing above ground floor openings. Galvanised metal straps to sides of floor joists. | Mansard roof. Roof covered with clay tiles. |
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WHATLING HOUSE IDENTIFICATION CHARACTERISTICS
- 2-storey semi-detached houses.
- Medium pitch hipped or mansard roof covered with clay
- or concrete tiles.
- External walls rendered [pebbledash] throughout.
- Some houses have bay windows at ground floor front
- elevation.
- Flat canopy to front door.
SURVEYORS NOTES
Vertical cracking in dense aggregate RC external walls.
Horizontal cracking in dense aggregate RC external walls over ground floor windows.
Absence of vertical movement joints in external walls.
Damp problems in dense aggregate RC external walls.
EASIFORM TYPE I IDENTIFICATION CHARACTERISTICS
- Bungalows and 2- and 3-storey semi-detached and terraced houses.
- Medium pitch hipped or gable roof covered with concrete tiles.
- External walls fair-faced concrete or rendered.
SURVEYORS NOTES
Aggregate may contain unstable fractions of unburnt coal.
The system was also used for flats.
EASIFORM TYPE II IDENTIFICATION CHARACTERISTICS
- Bungalows and 2- and 3-storey semi-detached and terraced houses.
- Medium pitch hipped or gable roof covered with concrete tiles.
- External walls fair-faced concrete or rendered.
SURVEYORS NOTES
Complete carbonation of concrete cover to dense RC external walls, particularly in properties built before
1960.
Minor cracking of RC external walls.
Out-of-plane movement of some flank walls.
Non-carbonate carbon content of clinker concrete inner leaf of external walls sometimes exceeds 10%.
The system was also used for flats.
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