So, a very knowledgeable guy wearing a polo shirt with a logo on it told you that if you installed drain tile in your basement that it wouldn’t leak any more. Sounded good to you so you signed on the bottom line. But wait a minute, what kind of pipe are they going to put into your basement?
Believe it or not, there’s a big difference between the two main types of pipe used for interior drain tile and a knowledgeable basement waterproofing company will install the right one for the job.
Corrugated HDPE (High Density Polyethylene) – Corrugated HDPE pipe is usually black and is flexible; it comes in 100-foot coils. When used in waterproofing, a four-inch diameter is common and the pipe is perforated with small slots all the way around, situated between the ribs.
PVC (Polyvinyl Chloride) – PVC pipe may be familiar to you as the rigid, white stuff often used for plumbing drains. The kind used in waterproofing is a larger diameter, usually four inches, and is perforated with large holes. It typically comes in ten-foot lengths.
Which Pipe is Better for Interior Drain Tile, Corrugated or PVC?
In most applications, the corrugated pipe performs better. However, the City of Chicago building codes require the use of PVC pipe in drain tile, regardless of other factors, so it will always be installed in Chicago homes.
There are several advantages to corrugated drain tile:
Flexibility – Since the corrugated pipe is flexible, it can be installed in longer runs without right-angle elbows or a lot of glued joints. This prevents water back-up and eliminates opportunities for clogging by iron bacteria or debris that might infiltrate the system. Water won’t flow as easily through PVC because of the numerous 90-degree bends required to navigate the perimeter of the foundation.
Drainage – Because the corrugated pipe is perforated all the way around with many more openings, water won’t sit in the pipe but will quickly drain out. With PVC, the openings are far fewer and water can accumulate.
Less Likely to Clog – In corrugated pipe, the perforations are numerous but small so only tiny bits of debris could possibly enter the pipe. Further, the perforations are not directly on the surface but buried between the ribs of the corrugations, making it more difficult for debris to find its way in. PVC pipe has much larger openings directly on the surface of the pipe and is more prone to clogging.
Are There other Reasons to Avoid PVC?
PVC pipe has its uses in waterproofing and managing water around your home and we’ll discuss some of those in another post in the near future. However, other than complying with those inexplicable building codes in Chicago, I’d recommend avoiding PVC in interior drain tile installations. It does have its advocates but many of their arguments don’t, no pun intended, hold water.
If PVC Doesn’t Clog, Explain the Clean-outs! – Waterproofing companies who push PVC for interior drain tile will tell you that it doesn’t clog yet they always insist on installing clean-outs in a drain tile system for “maintenance.” This doesn’t seem logical to me. If you need maintenance, that means you have a clog. If your system doesn’t clog, you don’t need clean-outs.
The truth is that PVC can clog. Those larger openings can admit gravel and other sizeable debris, along with soil, that accumulates and cuts down water flow or eliminates it altogether.
PVC is strong; Corrugated Pipe can be Crushed – Yep, PVC is stronger than corrugated pipe; I’ll freely admit that. However, drain tile is buried under the basement floor, in a foot of gravel. What exactly is going to crush it, a visiting Tyrannosaurus Rex stomping around your basement?
PVC Costs More – Not only is the pipe itself more expensive but it’s more labor-intensive to install because of all the joints that have to be fitted and glued.
So, pipe does matter. If you’re a Chicagoan, you’re limited to PVC for your interior drain tile so make sure the company that installs it does it the right way and doesn’t sell you “maintenance” you don’t need. Elsewhere in the area you have options, so make sure you quiz that guy in the polo shirt about the kind of materials his company will use.
In the 55 years we’ve been in business, U.S. Waterproofing has done thousands and thousands of drain tile installations. We prefer to use corrugated drain pipe for interior drain tile whenever possible so please ask for our free advice on what’s right for your basement.