One of the Grosvenor landscaping teams has recently completed a project for a client near Haywards Heath, West Sussex. Grosvenor Landscape Technologies had been recommended to the client by a friend whilst discussing the restricted access to his front door.
The solution to the problem was to alter the embankment that sloped down to the paving by installing a dwarf retaining wall so as to extend the entire area. A number of options were considered that included constructions in masonry (brickwork, concrete blocks with a painted render face or Wealden sandstone with brick quoins) or in timber. It was clear that timber would be the prefferred choice. When a timber retaining wall the method of construction is dependant on the desired shape being created. Angular shapes suit laying the timbers horizontally and curved shapes can be achieved by installing the timbers vertically (see photograph which shows a Chestnut retaining wall with an integrated bench seating – the wall is capped with a decorative lead flashing to protect the exposed end grain).
Due to the nature of the site an angular design was settled upon which just left the decision on what timber should be used. Pressure treated softwood was one alternative but was discarded as available timber could not sourced locally. This left either Chestnut or Oak. Oak was the choice made and you can see from the photographs it fulfills all the requirements of both form and function. Much of course is written about the virtues of English Oak, however I would just make a short comment to anyone who may be looking for a hardwood that performs exceptionally well but also offers an ecconomic advantage. The point I feel should be bourne in mind is that the traditional material that farmers have used when putting timber in contact with soil is Chestnut – just consider all those miles of post and rail fences (see photograph) and stake and wire fences!!!
The Oak timbers were machined by a sawmill in the Horsham area and we were even able to choose the butt (see photograph) that would eventually become our wall. All the joints along the wall line are mitred to create the perfect fit and the timbers are fixed to steel reinforced concrete posts set in deep concrete anchors behind the wall. This method of construction eliminates future concerns of posts failing.
Once the embankment had been dug back and the wall constructed this left the brick paved area to be extended to meet the new wall line. You may well be familiar with block pavers which are a decorative concrete product, however, traditionally bricks or brick pavers were used. Brick pavers differ from a standard brick in that they not only have a finish to there edges but also to the top face. This also makes them very useful as a wall capping although few brick yards produce pavers to match their brick range – luckily our closest brick manufacture offers this service.
The final job was to back fill behind the wall with a free draining sandy loam topsoil ready for planting.
Should any of the services we provide be of relevance to a project you are considering please do contact Martin Blake.