Eventually old copper potable water pipes in building oxidize (or corrode) and the pressurized water begins to leak out. So may have heard of slabs leaks or pipe leaks in walls, and to replace these pipes is very costly and invasive.
Epoxy pipe lining is an alternative that works very well and is usually cheaper than the total cost of pipe replacement, which includes the demolition and repair cost of all surfaces affected by the replacement. It is used extensively in the Long Boat key, Sarasota, Venice and Naples areas in Florida. Here's how it works:
First the pipes are sandblasted from the inside to remove all the old oxidation deposits. This is done by blowing air with entrained silica particles through the pipes. There is some "blowing" equipment upstream and "receiving" equipment downstream to capture the debris. Once the pipes are clean, air is again blown down the same pipe but this time along with an epoxy liquid that hardens in a few hours.
The epoxy used is the same food grade epoxy that you have seen on the inside of food cans, so it's perfectly safe for consumption. This epoxy pipe lining is ideal for drinking water pipe lining, as it is very thin and very hard. But hard doesn't necessarily make it strong, as it can crack under load-bearing applications, like under roads or wall footers. So in the Long Boat key, Sarasota, Venice and Naples areas in Florida, we find epoxy pipe lining is used mainly in condo walls and floors, but not for sewer pipe relining.
Can you re-line Orangeburg Pipe?
First let's start with what Orangeburg pipe is. Back in the Second World War all the iron supply was directed toward the production of weaponry, which meant that a new material had to be developed for plumbing to replace the missing cast iron.
As a result a new material called "Orangeburg" consisting of wood fibers (like paper) mixed with tar and was manufactured in Orangeburg, PA. This material was the used to make sewer pipes, millions of miles of it. It is estimated that Orlando and Tampa have 200,000 miles of Orangeburg pipe under their floors. Everything seemed OK with Orangeburg for a while, but then some serious issues started to arise.
Any solvents like nail polish remover, paint thinners and rubbing alcohol that went down the drain would dissolve the tar, weakening the sewer pipe. Usually the bottom of the pipe would go first. On sewer pipe video inspections, the bottom of the Orangeburg sewer pipe appears to bulge upwards. These bulges create blocked drains as debris is captured in these areas.
The next common drain problem with Orangeburg pipe is root intrusion. Root intrusion with cast iron pipes and clay sewer pipes (VPC) usually occurs at broken, cracked or pipe joint areas. But with Orangeburg pipe, the tree roots grow straight through the pipe walls anywhere, creating blocked drains and backups. Video's of pipes under Orlando and Tampa show the characteristic oval egg-shaped cross section of these pipes created by the load on top of the pipe flattening it out over time.
Orangeburg pipe can be re-lined, but pipe bursting is more commonly used, where a new pipe is pulled through the old pipe cavity using a pointed conical "head" that breaks up the old pipe to make way for the new pipe pulled in place behind it for pipe replacement. (ArticlesBase SC #1616729)