Whether you are constructing double sides free standing walls as shown here, or single sided retaining walls, the method of coping the multiple sections of the walls i.e. concrete block backing or hearting of the walls, it is very important to prevent water from penetrating the top of the walls and entering the ‘layers’ of material.
As shown here, the wall has been finished or coped in brick, one and a half brick wide (33cm approx.) to complete a double-sided flint wall with solid concrete blocks at the centre. These blocks have a substantial number of brick butterfly style ties set into the joints at 45cm centres to ensure a close bond between the mortar used in the flint walling process.
Please see the construction techniques used in the building of the walls elsewhere in The Library. For your interest, the walls were built over very substantial concrete foundations, 90cm wide x 60cm deep with triple lengths of 20mm steel reinforcing to ensure a solid base.
Unusually, the piers do not have steel bars set into the hollow section of the brick piers – a practice I would normally employ – the piers being hollow and are treated as ‘break points’ or ‘shear points’ as the previous boundary to the site had a panel fence, which had been demolished twice in recent years by vehicles traveling too fast through the village. Due to the nature of the walls, any trauma caused by a crash could/would have demolished the entire length of the wall, so I decided to try and limit the damage potential by creating a sectioned construction.
The bricks used were Old Farmhouse Blend – a new brick sold to resemble a second hand and antique appearance. Due to the somewhat battered and chipped shapes, I found them very easy to lay. Even a non-brick layer such as myself can manage to make an attractive job quite easily using a forgiving module such as these!
To prevent rainwater or moisture from entering the three sections; flintwork, concrete block then flintwork, a double overlapping row of standard slate roofing tiles, sawn to length using a 10cm angle grinder, were laid across the top of the flint work, levelled using a 50mm x 50mm timber bar similar to the one shown at the base of the wall, which was set at the appropriate height between the brick piers.
These slates were carefully and precisely set into mortar as a double thickness twin row, then capped with brickwork to finish the project, thus preventing any ingress of water which may have caused damage by frost action/expansion. Their presence adds another dimension to the design attraction by adding a ‘shadow line’ to delineate the change from random flint to the more formal brickwork.
(On a separate subject, each panel of flint work, three metres long x 1.2m high, was built in a single eight hour day by myself and one skilled labourer. Total square meterage 3.9 metres per panel. There were three sections in total, two straight and one curved, total length 13 metres, fair face both side i.e. six panels. Using the methods as shown under the Hints and Tips articles on Flint Walling elsewhere in The Library)
Note too the accurate colour match of the mortar, a vital matter when building facework of any kind.)