Polymeric sand in cold weather! Creative solutions to helping it cure?
I am about finished with an 8 ft x 13 ft patio, and the plan is to bond the pavers with polymeric sand. It's just starting to get down to freezing temps overnight, and I'm willing to take some chances with some creative solutions to cure the sand before it gets even cooler.
I understand that it's generally a bad idea to attempt poly sand in cold weather. But entertain my dumb idea: my patio is small enough to where I can cover it with a tarp like a tent, and I can leave a space heater in there overnight so that the sand is exposed to warm air. I am personally convinced that it's stupid enough to just work. Is this a terrible idea?
I also had the thought of bringing hot water out in a watering can from my bathtub. I needed to tamp the gravel that froze at one point, so I already did this, and was able to cover the whole area in about 5 trips or so. My only concern is that this is not a conventional way to set the sand, and am concerned that the hot water would flush the polymers right out of the sand without having an opportunity to cure.
What are your thoughts? I'm willing to take silly risks on this :) Worst case scenario, I get expensive regular sand, right? That's not so bad ;)
Edit: Decided to wing it and give it a shot. I thought I would attempt to heat the paver bricks overnight, and if that plan fell apart, go ahead with typical utility sand. Well, I successfully built a tent with a steel tamper, a hand truck, and tarps, and snuck a little battery-powered temperature and humidity sensor in there that I use with my home automation.
All throughout the night, the temperature hovered around 70F during a high 20s evening with less than 40% humidity! It worked so incredibly well that I decided that there was no reason why I shouldn't take advantage of this. With the bricks bone dry and warmed up, I did the poly sand today and it turned out absolutely excellent. I put the little tent back on it, and plan to leave it on there with a ceramic space heater running for about 3 more days. It's quite literally a summer day in there minus the sun! It's covered like a tent, too, so it will be protected from the rain while it hardens!
Here's some graphs of how well this is working out from the sensor! This is the humidity! The jump and drop was when I took the tarps off, did the poly sand, and put it back together. The humidity with the situation going is the same as indoors!
And here's the temperature! Staying toasty at about 73F! The little dip on the end is from when I opened it up to crawl in and check on it :)
This is honestly better than waiting for the spring! I'm so happy how this is working out!
I'm gonna be honest, it sounds like a bad idea. Disclaimer, i've never worked with this, but just describing your problem it sounds like you're going to run into ground temperature even if you manage to get the air temperature warm enough to set.
Yeah... this is my inner voice, too. I'm kinda thinking that I should just sweep utility sand into the pavers and not worry too much about the polymeric stuff. Honestly, the only reason why I'm thinking of poly sand is because I'm kinda thinking that the pavers would stand up better to legs of outdoor furniture. Although, perhaps if I work enough utility sand into the pavers with lots of tamping and brushing, it shouldn't be a big deal? I mean, it's not like all patios done right without poly sand are failing.
The biggest plus of polymeric sand over the utility sand would be that the utility sand will eventually grow weeds, where the polymeric won't. Do you want to be trying to kill weeds every year? If not, cover the patio with a tarp for the winter and use the polymeric next spring.
My town doesn’t allow polymeric sand so I have to use regular masonry sand. It hasn’t affected the stability of the pavers, but pulling weeds all summer is kind of annoying.
Maybe you use plain sand now and come back and do it when it’s warm.
Yeah, it does sound like a bad idea, and I'm thinking more and more that I should just sweep utility sand between the pavers instead and call it a day.
Why not just wait until late spring?
The only reason I'm trying to get ahead of this now (instead of waiting for warmer weather) is because I'm building a structure around the patio that will make it difficult to sweep or blow off the sand as it cures. It'll probably get everywhere and get nasty.
Although, it'll be a covered area too, so perhaps the advantages of the poly sand are marginal. There won't be any weed or moss issues, and it won't be exposed to weather basically ever. So perhaps I just shouldn't bother and sweep regular sand in. The benefits of poly sand probably isn't worth the very real risk of making my patio really nasty.
Look I know everyone is saying don't but I think you can do it pretty easily. So I have seen masons do brick and stone facades in the middle of winter. They had concrete blankets and diesel heaters. It worked just fine. I would get two tarps and a blanket and build a little tent with tarp, blanket, tarp. Then put a little electric heater in there. Newer electric heaters are much safer than the old ones with the ones exposed resistance elements. Just think you don't have to get it really hot. Not like it is going to catch fire until a few hundred degrees as long as the heater is not touching the tarp there is no real chance of that happening. Plus if it is just barely freezing at night then it really just needs to really work for a few hours.
You know what?? I figured that I miss all the shots I don't take, and thought I'd give it a try. I built a makeshift tent from two tarps held by a steel tamper and a handtruck held down with buckets of water. I have an automated home, so I put one of the temperature/humidity sensors out there and hung in the lower area of the tent with a coat hanger. I set a ceramic space heater on a couple bricks, and fired it up.
The results? It's currently sitting at 65F with 43% humidity, which is less than inside our home. I think the thermostat is even oscillating, so I'm going to go out there and turn it up. I'll have a graph of the temperature and humidity all throughout the night, but this is hotter and drier than a summer night! And it's in the 30s outside!
Here's a screenshot of the data from me bringing the sensor outside, handling it, and letting it be in the tent:
So yeah, this is going to work great. I'm letting the pavers warm up and dry out overnight, then sometime midday, I'm definitely doing the poly sand. I'll make sure I get it cleaned up and ready to leave alone, then I'll cover it just like I did. Seriously, this is going to work better than waiting for the spring.