Up until the 1950s most drain pipes consisted of short lengths of clay pipe. Each joint was packed with tarred hemp and carefully sealed with sand and cement. Ask Ian Porter one of our directors. He installed pipes using this method!
Then pitch fibre pipe was introduced, at first this consisted of pulped paper or wood fibre impregnated with bitumen and formed into tubes. Later other products were incorporated. The drains were relatively inexpensive to buy and fast to install and became very popular up to the early 1970s. They have performed very well for their anticipated life span of forty years, however many problems are now occurring as they deform or de-laminate with blisters forming that cause blockages.
DON'T WORRY most faulty pipes can be fully restored, re-rounded and returned to service for at least another 50yrs (probably much longer) The method does not damage the surface above and causes minimal disruption at a fraction of the cost of excavation and renewal. The full integrity of the drain can then be restored by resin lining. Please see the next section on Resin lining.
It makes good economic sense to re-round and resin line a defective pitch fibre pipe. In nearly every case a substantial saving can be made. For example in the case of a 100mm pitch fibre pipe at a depth of 1.8m in a hard surface the calculated monetary saving would be in excess of £6000.In itself this would be a worthwhile saving. When you consider the saving in carbon footprint it becomes the only sensible choice. Taking into account the savings that resin lining gives over replacement there is a saving of 248 units on soil volume of excavation alone. In total the units for excavation and replacement would be 450 and that for resin lining would be 25. In fact the savings would be slightly more because the figures for the specialist disposal of pitch fibre to a land fill site have not been calculated.
It makes sense then to resin line wherever practicable, save money and help to save the planet at the same time. Not all savings will be as advantageous as this example, if for instance the excavation is all ‘in the soft’, however worthwhile savings will still be made.
If deteriorating pitch fibre pipes are not attended to they will undoubtedly fail leading to an expensive (in every way) excavation and renewal.
Not all collapsed pitch fibre is suitable for re-rounding and resin lining, however, we have over a 95% success rate and this method should always be considered first.