effects of cold weather on portland cement

My husband and I are planning to have one and a half inch thick bluestone layed on an existing 30 year old poured concrete patio that is over a garage. While we are not able to see any obvious cracks in the concrete slab, there is an area toward the middle where water leaks into the garage below. Our mason plans to set the bluestone in portland cement with a sealer mixed in. I have 2 questions: Should we also apply a liquid sealer such as drylock beforehand. Also, we are doing the job late in the fall in New England when temperatures are freezing at night. Will the cooler weather prevent the portland cement from properly curing? I have read about hydration problems with concrete. Does the same problem occur with portland cement and grouts and mortars?

Thanks for your help!


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Owner D&D Stone Brokers
by: Don

If it's under 45 degree's you may want to reconsider laying bluestone this late in the season, not only will you have issue's with the cement, but the bluestone may crack or not adhere at all. I sell alot of bluestone and most of the quarry's are getting ready to close , because of the weather.

be careful
by: David

Dear Susan,

You do need to be careful with Portland in the winter. We just talked to a lady in the D.C. area that had flagstone laid in the winter and it busted up.

When my dad has done it in the winter, he has insulated blankets and heaters so the Portland won't freeze up.

My dad has never used an additive called Drylock so I can't comment on that. My dad is a big believer in using a quality sealer after the patio is laid. He's had good luck with that, but maybe conditions are different in the New England area. We are in Colorado.

I hope that helps you out!

Great luck!!


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