Downspout Lining

Downspout or vertical lining has been around for some time however there were limitations as to what could be done when the liners were inflated using water, this was mainly due to the sheer weight of the water on a vertical drop and the capacity for the lining materials and inversion hoses to hold that weight. Now with the development of air based inversion techniques and flexible liners we are able to reline long vertical lengths of pipe work whilst at the same time negotiating multiple bends.

The main difference from drain lining is that the bends used on down spouts are often sharp or short radius compared to the longer sweeping bends used in drainage, the pipe sizes used in downspouts can also vary from underground drainage pipes with sizes such as 3½ inch or 5 ½ inch being used and lead downspouts were formed on site to the size that suited on that particular day.

Access is usually very limited on internal downspouts and it is sometimes necessary to make access into the pipe work at some point, then we have the health and safety aspect to consider and how you can get men and machinery onto the roof in a safe manner.

Surveying Downspouts

It is vital that a thorough camera inspection be undertaken to assess the condition of the downspout prior to any lining works being attempted, this will tell you how the system was constructed, the pipe size and how many bends there are.

The survey may also show that there is actually an obstruction causing the problem as opposed to a cracked or fractured pipe, we have found bottles, aluminum cans and tennis balls lodged in downspouts in the past.

Why Downspouts Need Relining

Where downspouts are on the outside of a building it is fairly obvious when they are failing and where they are leaking from, internal downspouts are usually concealed or built into pillars and walls so leaks can go unnoticed for years with the damage caused often manifesting some distance from where the leak actually occurs.

It is more often than not cheaper and easier to renew external downspouts then reline them but when the downspout is concealed or cast into a concrete pillar the very process of accessing the pipe work can be extremely costly not to mention the upheaval and disturbance this can involve.

Why Downspouts Fail

The material used to construct the downspout will depend on the age or the building, cast iron is by far the most common material and prone to corrosion with lead downspouts often failing due to corrosion, wear and tear and impact damage during a building conversion. Modern plastic pipes can also fail if a sealing ring in a joint is disturbed when the pipes are joined.

We also reline systems for preventative maintenance reasons, most cast iron pipes had a 100 year working life expectancy if they were coated when manufactured, or 50 years if they were not so it makes sense to reline them if the building is undergoing a major refurbishment.