# Is PVC too brittle in cold for drain under a paver patio?



## BrandonC_1972 (Apr 28, 2012)

I am installing a large paver patio and will be using a channel drain to help with the significant runoff that it will generate. The paver drain has 1 1/2 inch schedule 40 drop outs.

My current plan is to connect these drops to 4 inch sch 40 solid core PVC using a 4x2x4 TEE/WYE. The drain and the 4 inch pvc will be parallel with the pavers and the T will be vertical if that was not obvious.

Everything I have seen indicates that PVC is more brittle at lower temps. The drain pipe and fittings will be covered by 12 to 24 inches of gravel being under the pavers. Obviously this is not below the frost level. Should I be concerned over time with shifting, freeze thaw, hydro-static pressure, etc with such a big pipe or the fittings cracking? 

It appears that Type 2 or Type II PVC is rated for lower temps but I can't easily find any retailer that sells it. Is it worth looking into that?

While I noted that my gutter downspouts empty into cellular/foam core PVC, I viewed it was worth the 5% difference in priced to go with solid core PVC.


I am also planning on using tiger flex pvc to connect the 4 inch pipe to the channel drain to make it easier to connect the bottom outs after I compact the base and level the drain with where the pavers will go. Any concerns (crush, longevity, freeze, etc) of using tiger flex pvc for drainage? It is obviously good for my swimming pool but that always has some water in it where the drain will effectively be empty most of the time.

Maybe I am being too cautious considering that downspouts and french drains not only use PVC above the frost line but they are using lesser PVC such as foam core or the thin wall PVC with holes in it. But I would prefer to not have to redo the patio once I have it in because of a cracked PVC pipe under it that no longer drains. 

I am in western PA and the size of the patio is about 18x48. There will be two paver drains (Quaker Plastics) will run the entire length. One end of the patio will abut my house. The opposite end will abut my pool concrete. The sides will have a small retaining/accent wall. In addition to the paver drains, there will be corrugated PE at the bottom of the aggregate under the pavers to get any additional water. My project is stalled at the moment because I am waiting for my local tool rental to get their Dingo back. Every time it rains, I have to shop vac 200 gallons of water out of my excavation site so thus the emphasis on doing these drains right.


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## Thunder Chicken (May 22, 2011)

It does get brittle in the cold, but it is only a problem if it is going to take impacts (i.e. you are going to smack it with a hammer). If it is buried properly it should be able to take static loads without a problem. Do check your local codes for the definition of "buried properly".


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