The Garden Guide

Lined concrete - review

Pond Construction Guide

Concrete, brickwork, blockwork and masonry structures can be used in conjunction withwaterproof membranes. The membrane can be:

  • on the inside of the structure
  • on the outside of the structure
  • sandwiched between two structural layers
  • a combination of the above

The following points should be considered when choosing between the above alternatives:

  • when the membrane is inside the structure, it may difficult to keep the membrane in position during the construction works
  • if brickwork, blockwork or masonry will be saturated in water then the materials must be frost resistent in cold climates
  • if the membrane is on the inside face of the structure then it is exposed to UV light and to physical damage. It will also be unsightly
  • if placing a membrane inside a rectangular structure it is best to have it pre-formed to a box shape to fit the structure exactly (if membrane comes in a roll it has to folded at the corners, risking damage and ugliness)
  • membranes can be fixed to concrete with adhesivesand secured with a clamping bar and mastic seal (see detail)

The membrane can be(1) sandwiched (2) outside the structure (3) inside the structure - a lapped joint in the membrane can be made at the point where the vertical section of the liner meets the horizontal section (bottom left)