Why not to store RVs on jacks/blocking in winter

Harvard wrote:
This is the second TT where I have had this happen, both were purchased as used units which were 8 and 12 years old when they ended up permanently parked on blocks at our acreage (in Alberta). They obviously survived Alberta winters sitting on their wheels and front jacks and only had a problem when we put them on permanent blocking.

Correlation does not equal causation.

Far more likely is as the vinyl ages, the plasticizers evaporate (you are looking at 10yr old RVs).

Then you get a really cold snap and it tries to shrink but is held down on the edges. Being less stretchy than when new, it cracks rather than stretches.

The flex in the frame is no where near enough to damage the vinyl.

Harvard wrote:

GrandpaKip wrote:

Harvard wrote:
If the RV is sitting on front and rear blocking AND has vinyl floors, there is the risk of flexing the cold vinyl which will crack in the process. The flexing is caused by the tires changing their load bearing with temperature changes. Just leave the RV sit on its wheels and front jack. Been there, done that...

If you were told this in order to avoid any warranty work, well, you might have been snookered.
If not, then, by all means, store it the way you feel best.

This is the second TT where I have had this happen, both were purchased as used units which were 8 and 12 years old when they ended up permanently parked on blocks at our acreage (in Alberta). They obviously survived Alberta winters sitting on their wheels and front jacks and only had a problem when we put them on permanent blocking.

What you are saying is not making sense. You are saying the flex is caused by temperature changes in the tires. Then you say to leave the RV sitting on its wheels and front jacks, which involves the tires. Unless you do something really odd and take the tires off the rims for the winters.

Stabilizer jacks are not meant to be 100% load bearing for any period of time. You are more likely to get frame flex from the stab jacks flexing under these conditions, than from the tires.

How cold does it get sometimes in Albirda?

The insulated steel walk in door on my garage will bend completely away from the puffy seal at the bottom from the contraction of the outside skin. So 30 ft of trailer frame will move a little.

I have personally carried propane in a bucket. It boils at -40C/-40F at 1 atmosphere.

Early 1980’s China origin wrenches - leave one outside for a few hours and you could hit it with a hammer amd break it into pieces.

Oil furnaces, Diesel engines, and turbine aero engines all ran on the same fuel - jet A aka -50 heating oil, aka diesel -50.

Trackrig wrote:
Mine are stored near Fairbanks, AK without a problem. I sort of level it with the front jack and I DON'T use the corner jacks. Never had a problem with the vinyl or anything else.

Bill

and that's the way these units survived winters without incident up until we got a hold of them :B

Mine are stored near Fairbanks, AK without a problem. I sort of level it with the front jack and I DON'T use the corner jacks. Never had a problem with the vinyl or anything else.

Bill

I am sorry but I have to completely disagree with this premise.

First of all the amount of deflection occurring while on jacks to the middle part of the floor is minimal at best.

Keep in mind that underlying the vinyl flooring is a subfloor of either plywood or some other type of composite wood panel. That is supported by 2x4 or metal joists that sit upon the frame.

The effect of the above is a strong structure and fairly stiff.

You are much more likely to have problems and flexing WHILE HAULING in cold weather.

On a recent trip to Alaska in March of 2017 when the overnight and morning temperatures along the Hiway were -20 to -30 my trailers floor and flooring experienced no problems at all.

In addition I had recently installed REAL tile in my bathroom and so called "floating" flooring both in the entry and the bathroom. None of which actually floats as they are essentially "tied down" by being up against one wall or under a threshold.

I had absolutely NO problems with any of it. That same system has been in the southwest with temps above 100.

Also these trailers are stored for long periods during the winter at or near the MFG outside and hauled to the dealerships during cold weather.

Finally if your trailer frame is so weak as to deflect more sitting still than under tow which it would have to do to cause the OP's problem than you have bigger problems than the weather.

Your theory may well be correct, but you have nothing relative to causation.

For instance, ground heave in the winter could possibly cause three corners of a RV to lift 3-inches while the fourth doesn't lift at all (we're talking possibilities not probabilities for the purposes of making a point). That would be enough to possibly cause the floor to crack. Your relating the cracking to tire load bearing changing is pure speculation with no basis in fact to make it believable. There is just not that much change in a tire due to temperature.

and NO, it was not used (no occupants) at all over the winter months.

Harvard wrote:

DownTheAvenue wrote:

Harvard wrote:
If the RV is sitting on front and rear blocking AND has vinyl floors, there is the risk of flexing the cold vinyl which will crack in the process. The flexing is caused by the tires changing their load bearing with temperature changes. Just leave the RV sit on its wheels and front jack. Been there, done that...

For this to be possible, the tires would have to expand and contract significantly, even visibly, while the the front and rear "blocking", presumably the stabilizer jacks, would remain constant regardless of the varying temperatures. If the floor warped enough to crack the floor covering, the siding and roofing would have gaps enough to put your hand through!

The way I see it if the tires were about 50PSI at 70F in the summer they would drop to about 40 PSI at -10F in the winter. With both ends up on blocks the tires would be supporting less weight in the winter then they did in the summer. I may not have the science down pat but I do believe in the cause and effect aspect of this experience.

You are exactly correct. The tire pressure will vary slightly summer over winter, and your estimation of the pressures may be accurate. The question is how much will the lower air pressure cause the trailer to lower. Very, very little. I bet not enough to even cause an exterior door to jam. Certainly not enough to cause the interior floor to buckle so much that the floor covering rips apart!

In extending the stabilizer jacks, you can often watch, especially at the back, the trailer actually rise as you tighten the jacks. That is more rise than you would experience in the scenario you have envisioned.

Your floor covering cracked due to the extreme cold you experience in the Winter. After all, living North of Calgary gets pretty darn cold! By the way, nice house!

DownTheAvenue wrote:

Harvard wrote:
If the RV is sitting on front and rear blocking AND has vinyl floors, there is the risk of flexing the cold vinyl which will crack in the process. The flexing is caused by the tires changing their load bearing with temperature changes. Just leave the RV sit on its wheels and front jack. Been there, done that...

For this to be possible, the tires would have to expand and contract significantly, even visibly, while the the front and rear "blocking", presumably the stabilizer jacks, would remain constant regardless of the varying temperatures. If the floor warped enough to crack the floor covering, the siding and roofing would have gaps enough to put your hand through!

The way I see it if the tires were about 50PSI at 70F in the summer they would drop to about 40 PSI at -10F in the winter. With both ends up on blocks the tires would be supporting less weight in the winter then they did in the summer. I may not have the science down pat but I do believe in the cause and effect aspect of this experience.