All Spa Owners Should read this: Valuable Lesson Learned: ALWAYS Pull hot tub cover cores out and check them when you receive a new cover

[DangerBoy]

This is a cautionary tale for anyone who buys or is about to buy a replacement hot tub cover and it provides useful information to all hot tub owners.

I just received my new Deluxe cover for my '95 Hot Spring Grandee. It has a 5" x 3" taper, 12 mil vapor barrier (2 separate 6 mil wraps) and a whole bunch of add-on features that ran the price up to about $620 CAD including an $85 surcharge for one dimension of the cover being over 96".

Acting on the advice of an experienced friend, the first thing I did after getting it unwrapped was pull the polystyrene cores out of the cover to inspect the quality of the deluxe 12 mil wrap I paid a lot extra for and ensure that I got the wrap I paid for. To my absolute dismay and horror I found that the vapor barriers on BOTH CORES had been accidentally cut with a razor knife and hastily repaired with a strip of 2" packing tape. The cuts went through both layers of the barrier. One was nearly 7" long and the other about 5.5" long. I have marked the extent of the cuts with colored tubing in the attached photos.

One of the packing tape repair jobs was very hastily done and completely shoddy. A lot of the tape was creased and wrinkled so it wasn't even sealing the cut. Water would've started infiltrating the core almost instantly. The other repair jiob was a little better but still not very good. Besides that, I doubt the packing tape would've held up very long under the conditions it would've been subjected to and since one of the cut locations was along the inside edge (i.e. inside the fold), I suspect that core wouldn't have lasted very long before becoming waterlogged. The other core was cut along an outside edge which is exposed to the environment so may have lasted a little longer before getting waterlogged. But let's be clear here: The quality of the repair job is not what's at issue here; covers should NOT be leaving a hot tub cover factory with cuts in the core vapor barriers no matter how well the repairs to the cuts are done.

I took numerous photographs of the cuts in the vapor barrier and also of the cover to show that the cover was intact and not cut to prove it was not us who had made those cuts when we were cutting the shrink wrap off the cover.

I called the company who made the cover and luckily the phone was answered by the owner. I explained the situation to him and he told me to e-mail him all of the photos I took in full resolution. I put all 20 or so of them in a zip file and sent it to him through WeTransfer.com's excellent free file transfer service. It was late on a Friday afternoon when all this happened. He downloaded them right away and wrote back a minute or two later to tell me he was going to have a "little chat" with production on Monday and would get back to me with a resolution afterwards. He'll have the whole weekend to fume over it before he talks to them Monday morning. Boy, I sure wouldn't want to be the employee/employees responsible for this problem on Monday morning. Guarantee it will be a real bad start to the week.

My question is how many of their covers are going out like that? Both my cores were cut and poorly repaired. I'm probably one of the VERY few customers and perhaps the only customer that has ever checked the cores/wraps upon delivery. If covers only go out like that "once in a blue moon", what would be the odds then that the one guy who ever bothered to check his cover would find the core wraps on BOTH cores were cut clean through and shoddily repaired? Astronomically low, methinks. But if covers are going out like that all the time then it wouldn't be so surprising that I found what I found, would it? I put that question to the owner as well. I bet that's got him thinking.

So the lesson for all of us hot tub owners is to always pull the cores out of your new hot tub covers to inspect the core and vapor barriers as soon as you take delivery of it. Who knows how common this might be? It might happen all the time but since virtually no one ever bothers to check, it probably goes undetected 99.999% of the time.

 

[ajw22]

WOW! Good catch. And it sounds like your friend has seen this before.

 

[DangerBoy]

If no one ever checks the cores when they get them or for that matter, ever, how many people are getting something like I got or don't get the vapor barrier they paid for and never know?

From now on, when I place an order for a hot tub cover I'm going to tell them on the order that I am going to be thoroughly checking the core and vapor barrier to make sure the seal is good, the barrier is fully intact and that I got the wrap I paid for so NO "FUNNY BUSINESS"! And from now on I will ALWAYS check my new covers inside and out the moment I get them. I advise everyone who buys a hot tub cover to do the same.

The company I bought from has got a good reputation. If covers going out like mine did were really rare and if I'm one of the very, very few that ever checked their cores, the odds of me finding cuts in both core wraps would be astronomically low. Much more likely that it's a common thing. Is it just this company or industry wide? Who knows? Only way to know is for everybody to do their due diligence and inspect the cores in their covers to make sure the vapor barriers are intact/undamaged and that they got the vapor barrier they ordered and paid for. You pay handsomly for upgrades to the vapor barrier thickness, how are you going to know if you got that upgrade if you never bother to unzip the cover and inspect the vapor barrier? What I found shows you can't blindly trust cover companies to deliver a perfect product. That's a valuable lesson to have learned. Spread it around.

 

[frogabog]

Thanks for your investigative reporting! This will help people in the future searching for info. You may wish to modify your thread title a little though to include key words like spa cover or vapor barrier which will make it easier to find years down the road.

 

[DangerBoy]

Thanks for your investigative reporting! This will help people in the future searching for info. You may wish to modify your thread title a little though to include key words like spa cover or vapor barrier which will make it easier to find years down the road.

That's a good idea. I went in to edit my original thread but couldn't see where I could enter in keywords. Can I still do that after making the original post? How?

MOD note: I added to the title.

 

[Pool_Medic]

I think you will find those cores will hold zero water. I’m not even sure why they wrap them, I assume it’s so no little snow balls happen when they slide it into the cover. Am I wrong?

 

[Arobbert]

I think you will find those cores will hold zero water. I’m not even sure why they wrap them, I assume it’s so no little snow balls happen when they slide it into the cover. Am I wrong?

They will soak up a lot of water. It will make them very heavy and will greatly reduce the R factor. I recently had a local place replace my foam. It cost about half as much as a new cover. The vinyl was still in decent shape.

 

[DangerBoy]

I think you will find those cores will hold zero water. I’m not even sure why they wrap them, I assume it’s so no little snow balls happen when they slide it into the cover. Am I wrong?

Yup, you're wrong. Expanded Polystyrene (EPS) cores are tremendously absorbant. The foam itself is closed cell but there is a great deal of porosity and permeability between the individual expanded beads that is easily infiltrated and occupied by water. That said, the low density polyethylene (LDPE) wrap they put around the cores is also not waterproof by any means. It's just water resistant. The permeance rating of a 6 mil LDPE wrap is about 0.06 American perms. The permeance rating of EPS is in the range of 4.0 - 6.0 Perms. Two orders of magnitude higher than LDPE. But even with the LDPE vapour barrier being as water resistant as it is, hot tub covers typically become heavily waterlogged and effectively useless after 4 - 6 years and this happens 100% or nearly 100% of the time.

The cover I have on the tub now is likely 100% waterlogged. If you try to lift it or move it, it seems to weigh about as much as what the cores would weigh if they were nothing but pure water. It's actually unbelievable how heavy it is and probably 98%+ of the weight is water as the cover was feather light when it was new. Now it weighs about as much as a full sized '72 Buick.

This exposes my pet peeve about the hot tub cover industry. These LDPE wrapped EPS foam hot tub covers fail from moisture incursion 100% of the time and the failure time typically is maybe around 5 years give or take. Every month 165,000 hot tub covers go into North American landfills creating a huge waste disposal problem. That's the equivalent of over 6 BILLION styrofoam coffee cups going into our landfills every year. Despite that, the hot tub cover industry has not come up with an innovation or product to increase the lifespan of these covers in decades. Yes, I know there are a few companies offering longer lasting options but those come at a cost maybe 5 or 6 times higher than the conventional EPS core hot tub cover. But why would these companies do anything to change the status quo? It's clearly not in their best interests. There are no regulations or incentives for them to make their product any better and longer lasting so why would they make a change to a product design that they know is guaranteed to fail in 4-6 years and keeps their industry in business churning out 165,000 of them a month?

 

[frogabog]

Thanks for your investigative reporting! This will help people in the future searching for info. You may wish to modify your thread title a little though to include key words like spa cover or vapor barrier which will make it easier to find years down the road.

That's a good idea. I went in to edit my original thread but couldn't see where I could enter in keywords. Can I still do that after making the original post? How?

There's no keywords for you to fill in, I was just thinking of editing the thread title itself.

 

[Pool_Medic]

Well, I noticed when my cover needed replacing that it was the cover holding water, not the foam, the foam was light as day.

 

[Arizonarob]

@DangerBoy Kudos to you for inspecting your purchase properly. Thanks for posting up your findings to help others!

 

[Pool_Medic]

I still don’t get it. The foam cells used in covers is the same as the foam inserts for Hayward lights and in fact some skimmer winter plugs. Those retain zero water.

 

[DangerBoy]

I still don’t get it. The foam cells used in covers is the same as the foam inserts for Hayward lights and in fact some skimmer winter plugs. Those retain zero water.

These cores are made from Expanded Polystyrene (EPS) foam. They take little styrene beads, pour them in a mold and heat them so the beads expand to the size and shape of the mold. When they do that, there is a lot of pore space between the individual beads (high porosity) and those pore spaces are well connected giving the material a high degree of permeability. The Polystyrene foam itself is supposed to be closed cell so the water shouldn't be able to infiltrate the beads themselves - at least not as much - but the water easily infiltrates the interstitial pore spaces between the individual beads. This is why EPS has such a high permeance rating (like 400 - 600 times higher) than actual water resistant barriers like LDPE - which is considered vapour impermeable which is still not waterproof.

Permeance, or the rate at which water infiltrates a permeable substance, depends on a lot of different variables such as porosity and the degree of connectivity between the pore spaces (permeability) and the vapour or water pressure the material is subjected to. Given that the cores are sitting just a few inches above 104F water on one side, there is a fair bit of vapour pressure on the underside of the cores. In these conditions, even the much pore impermeable LDPE wraps the cover companies put around the cores still permit water vapour to pass through and permeate the cores at a fairly high rate. HDPE wraps would be an improvement but still wouldn't completely solve the problem.

Extruded polystryrene foam (XPS) is more homogeneous than EPS and doesn't have the pore spaces between the beads so its permeance rating is in the range of one order of magnitude lower than EPS and is considered a vapour semi-impermeable material. In contrast, EPS is considered a vapour semi-permeable material. This is the reason the foam boards you buy for insulating basements and walls are XPS and NOT EPS.

As such, cores made from extruded polystryrene would be way better than EPS but they're more costly to make (and wouldn't have to be replaced nearly as often) so pretty much all or maybe all of the conventional hot tub cover companies only offer EPS cores.

Again, this gets back to my pet peeve about the hot tub cover industry. I believe there are numerous ways they could make their product better and last much longer but none of them do any of those things because it's not in their best interest and no one is making them accountable for the mountains of waste their products create every year. So instead of striving to make a cover that lasts much longer and minimizes or at least reduces waste going to landfills every year, they have continued to make the same mediocre product and have not changed anything about the way they've made them for decades. 165,000 hot tub covers going into North American landfills every MONTH is unsustainable and needs to stop.

 

[calstar]

Really good(and depressing) information, thanks.

 

[Brussell]

EXACT Same thing happened to me last Autumn with a company called Affordable Spa Covers. I was told that cutting the sheeting is the "industry standard" to remove air when stuffing core into vinyl outer cover. The website says "Heat-Sealed". I asked to see a white sheet from the packing tape manufacturer stating that the tape is for permanent vapor-tight sealing of polyethelene sheeting used in a high-temperature, steam, and corrosive environment, he laughed at me. 3.5 months of phone tag and finnally they said that they would only replace it if I paid freight both ways which was more than the cover. I was forced to appease my disappointment in other ways. Contact me if you need details.

 

[Arobbert]

The warm moist air seeps in through an opening, condenses on the top and then saturates the foam. This is a big problem for those of us in Northern climates.

 

[Arobbert]

At least I could replace the foam for half the cost. Glad to have found a local supplier.

 

[DangerBoy]

The Hot tub cover company owner did contact me this week as promised to let me know that he had spoken to his production manager and that they will be sending me two new cores with fully intact wraps in about two weeks. He didn't elaborate on what he found out or how such a defective product was allowed to leave the factory. When I get the new cores I plan to leave them sealed in the shipping wrapping and maybe add some wrap of my own and then repair the problems with the first set they sent me and use those cores for as long as I can.

Epilogue

It wouldn't surprise me that what Brussel said is true and that cuts are routinely made in the PE wraps to bleed air out whenever too much air is entrapped in the wrapping to allow the core to be slid easily into the cover. Ie you think about it, they're always working at a frantic pace in these factories pumping out hundreds of covers a day. It's probably not the easiest thing to quickly wrap and heat seal poly sheeting around the cores without entrapping at least some air inside. The Vinyl covers are quite tight fitting so having just a wee bit too much air entrapped in the wrap may make it difficult or impossible to slide the cores into the cover. What are the workers supposed to do at that point? The assembly line's a movin' and they have to move the piece on. No time to re-wrap and re-seal. So what's the easiest thing to do? Cut the wrap witha razor knife, bleed out the air, hastily tape over the cut with some cheap-o packing tape, slam the core into the cover and send it on down the line. Why not?! No one ever pulls their cores out to inspect them so who's gonna know? Right? And if maybe 1 in 1,000 or 10,000 people do and find cuts like I did, you only have to replace that one set of cores IF they complain. That's WAY cheaper than sending dozens or hundreds of covers back up the assembly line to be rewrapped and re-sealed. Kind of a no-brainer when you think about it - assuming you're somewhat lacking in ethics and morals.

This makes total sense and falls right into line with my earlier supposition that covers are going out like mine did all the time. Heck, even the vast majority of them might be going out that way but we'd never know. Almost nobody bothers to check their cores when they receive a new cover and of those that do and find a problem, how many actually deduce that this may be a common thing vs an extremely rare thing and post about it on a forum like this or do anything to get the word out to the public?

 

[Pool_Medic]

Have you actually weighed these cores? I’ve cut apart plent of covers for disposal and I was positive it was the cover and not the actual foam that retained the water.

 

[DangerBoy]

Ive cut old waterlogged covers apart for disposal and the pieces of the cores were extremely heavy and literally oozing out absorbed water. I've also got a cover here that likely weighs at least 80 - 100 lbs and its a thin cover (only a 3.5 - 3 inch taper). It's physically impossibe for a thin vinyl cover to absorb that much water. The weight is all in the styrofoam.

Pool_Medic if you still can't get your head around the fact that EPS absorbs a lot of water despite the scientific data Ive provided you on its permeance rating, I suggest you do some searching on the internet about it. There are thosands of pages out there talking about how polystyrene foams used in hot tub covers, surf boards and basement insulation absorb a lot of water. Even hot tub cover companies freely admit their cores get waterlogged in order to convince you that you should pay lots of extra money to get an extra thick vapour barrier in an attempt to extend the cover's life.

Here's a link to a research paper put out by the EPS basement insulation industry that actuality shows how pathetic their product is but they spin the interpretation of the data in such a way that it makes their product sound superior to XPS insulation even when it's not. The paper shows that when EPS and XPS boards are subjected to an environment far less unfavourable (lower humidity and only 75 F) than foam boards in a hot tub cover, they absorb as much as 4.7% by weight in just 28 days. That's a very rapid rate of incursion. Try 4 years of continuous exposure in a high vapour pressure environment just 3" above a tub full of 104 F chlorinated or brominated water! Krikey!

https://www.airfoam.com/EPS-vs-XPS-Drying-Potential.pdf

What's so funny about this article is how they glorify the fact that the EPS boards dry out faster during a brief 20 day drying cycle than XPS boards even though they absorb 3 to 6 times as much water by weight in the same conditions and over the same amount of time. What this report actually shows is that EPS is far more permeable to water than XPS. Water can get in and get out of it a lot faster because the degree of connectivity between interstitial pore spaces in the material is much higher in EPS than XPS. These properties do not make EPS a superior product to XPS but if you read the article you'll see they spin the findings in a way that makes it seem so.

I read this paper and another one these guys put out attempting to prove EPS is much superior to XPS but as an Engineer who writes a lot of scientific reports, I don't think I've ever seen more subjective and manipulative presentation and interpretation of data and results. The ironic thing is, their data actually helps prove my point that EPS is a crappy material to use for insulation in a hot tub cover (or insulating a basement for that matter) but to hear them tell it, EPS is the best thing ever!