Tire Protection

[ljp]

I've been parking our trailer on wood 1x12's in order to keep the tires off the asphalt. Is there a product or better material to use that will help protect the tires?

[Lee]

Hi,

I may be wrong here but I'm not as concerned about the surface the tire sits on as much as protecting the tires from UV ex poser.

I keep tire covers on mine and the TT is parked on gravel.

[bsmith0404]

The boards you are parking on is pretty much the best surface. I also cover mine. If you decide to add covers, get the white ones as they will retain the least amount of heat. Also make sure you get the covers with the bungee cords that wrap around the back side of the tire or the wind will take them away.

[Festus2]

I've been parking our trailer on wood 1x12's in order to keep the tires off the asphalt. Is there a product or better material to use that will help protect the tires?

Every so often, someone asks this same question: "What is the best surface to park my RV on"? Almost always the answer seems to be wood or plywood. I have often wondered what is it about wood that makes it better for tires than asphalt? For some unexplained reason, there is something about parking on asphalt for extended periods that is "frowned upon".

There seems to be something in asphalt that is "bad" for tires over the long term. Is there some sort of chemical or other reaction that takes place between the tire and the asphalt that breaks down or somehow deteriorates the integrity of the tire? Is it the hardness of the asphalt as opposed to the "softness" of the wood that is not good for the tires?

My unsubstantiated understanding is that it makes no difference as to what type of surface it makes as to causing "flat spots" on tires. These spots are apparently caused by a combination of the weight of the RV coupled with remaining in one spot for a prolonged period - not the type of surface that it is resting on.

So if asphalt does not cause flat spots what does it do, if anything, to the tire? I realize that asphalt "attracts" heat and can become quite "hot" - especially in southern areas that get a lot exposure to the sun for most of the year. In these cases it would probably be the heat that might shorten the life of a tire. In other cooler climates, this problem may not be an issue and parking on asphalt would be "ok".

If someone out there has some documented "evidence" that parking on asphalt for storage or for other prolonged periods causes tire damage, I'd really like to read it. Is parking on wood "common knowledge", an unsubstantiated "fact", an old wives' tale or simply a myth?

[CWtheMan]

IMO, in regard to RV tires while in storage, when on the RV and it’s not elevated. There are four major factors to guard against. Here they are in alpha order.

Direct sun light
Causes the tires chemicals to migrate to the low point, leaving all other areas unprotected.

Trailer stored uneven (not level)
Causes some tires to support more weight than others which may cause overloading. (Tires do not have to be rolling down the road to be damaged by excessive weight).

Water intrusion
Always a dangerous situation. Prolonged storage on a wet surface will allow water to permeate into the structure of the tire. Almost all recommendations will be to elevate the tires onto wooden blocking materials. Pressure treated is best and sized to support 100% of the tire’s footprint. (I’ve always got my blocking materials from new home construction sites. I ask the site foreman. I’ve never been turned down). 2” thick blocks have been best for me. I cut a 45 degree bevel to prevent pulling the tire up onto a sharp edge.

Under Inflation/Overloaded (or both)
Under Inflation is the same thing as Over Loading. Both conditions cause the tire to rapidly degrade while just setting there. Don’t use your stored RV as a storage place for excess items.

Here is a picture of a couple of my tires while parked in storage.

http://www.irv2.com/photopost/showfull.php?photo=16759

[Javi]

Darn Festus, I really have nothing to offer on,your question.

But I kind of look at it this way. . . I park,our,trailer our 1" white limestone rock. Why you might ask. ... cause that's what the storage unit has chosen to use.

I also don't cover our tires cause the trailer is under a roof. But even if it weren't I doubt I'd cover them

Way I look at it, the tires is pretty much done in three years anyway so covering them and parking on a bunch of boards ain't gonna make much difference.

[bsmith0404]

My understanding is the oils in the asphalt along with the heat generated will both cause damage to tires that sit in one spot for long periods of time..stored. The link below provides some guidance for storage of tires, it also eludes to heat and oils.

http://www.tireindustry.org/sites/default/files/files/BMP-Storage-1113.pdf

[chuckster57]

I park on a concrete pad. Trailer came out of the backyard yesterday after 12 months of sitting. Checked/added air and good to go. No flat spots that I could see, I watch my tires in my mirrors like a hawk.

[ljp]

If one side of a tire is off the edge of the board 1-2" will this create a problem for the tire?

[CWtheMan]

Every so often, someone asks this same question: "What is the best surface to park my RV on"? Almost always the answer seems to be wood or plywood. I have often wondered what is it about wood that makes it better for tires than asphalt? For some unexplained reason, there is something about parking on asphalt for extended periods that is "frowned upon".



Asphalt has to be pliable to be properly molded into a road surface. As it ages its liquid chemical ingredients will dissipate and it will have to be removed and replaced. Until that happens its chemicals can be harmful to tires stored directly on it, especially in higher ambient temperatures for months at a time. So, some form of tire protection is needed.

On the other hand, concrete is porous causing it to hold water. We don’t want our stored tires to suffer water intrusion so we need to protect against it.

A short story: I park on asphalt. In the beginning I used 1/4" plywood. After the first period of storage of about a month I went to move the trailer to provide a 180 degree rotation of the tires and check their inflation pressures. I pulled the tires onto new 1/4" plywood and inspected the removed plywood. On the underside there was a complete print of each tire's tread area. I replaced the 1/4" plywood with 2" pressure treated wood. I wish I had taken a picture but I didn't.

[Festus2]

Water intrusion
Always a dangerous situation. Prolonged storage on a wet surface will allow water to permeate into the structure of the tire. Almost all recommendations will be to elevate the tires onto wooden blocking materials. Pressure treated is best and sized to support 100% of the tire’s footprint. (I’ve always got my blocking materials from new home construction sites. I ask the site foreman. I’ve never been turned down). 2” thick blocks have been best for me. I cut a 45 degree bevel to prevent pulling the tire up onto a sharp edge.

]

CWtheMan
Over time, untreated wood, plywood and pressure treated wooden blocks will become saturated with water and remain wet - especially here in the western pacific region over the Fall and Winter months. It would seem that there wouldn't be any significant difference as to the "wetness" between wood and asphalt.

In addition, can you explain how water permeates into the structure of the tire? Does it enter via the nylon threads or whatever else makes up the ingredients of the tire? Are tires not "waterproof"?

I'd still like to see some reliable references as to why it is recommended that the tires rest on wood.

[CWtheMan]

If one side of a tire is off the edge of the board 1-2" will this create a problem for the tire?

Probably the most damaging is the portion of the tire not supported by the wood is not supporting any of the axle weight. So the remaining section is probably in an over weight condition.

Also think - belt damage.

[Festus2]

CWtheMan -
Mmmmmm - a bit confused here. On one hand you seem to be saying that parking on asphalt can damage your tires but you also state that you "park on asphalt". You seem not be following your own advice????

FWIW, I park on plywood boards but I do that because everybody says I should.

[CWtheMan]

CWtheMan
Over time, untreated wood, plywood and pressure treated wooden blocks will become saturated with water and remain wet - especially here in the western pacific region over the Fall and Winter months. It would seem that there wouldn't be any significant difference as to the "wetness" between wood and asphalt.

I only use pressure treated wood and never use it long enough for it to hold water.

The chemicals in the asphalt may not be compatible with the tire chemicals when they permeate into the tire tread/sidewall.

In addition, can you explain how water permeates into the structure of the tire? Does it enter via the nylon threads or whatever else makes up the ingredients of the tire? Are tires not "waterproof"?

The only structure of the tire dense enough to prevent water intrusion is the inner liner. It does not protect the treads or sidewalls. It is under the belts so whatever they are made from can get wet.

I'd still like to see some reliable references as to why it is recommended that the tires rest on wood.

Here is a ref that may help. Go all the way to page 60 in chapter 4. The Michelin truck tire data book also has section about tire blocking. they also depict wooden blocks.

http://www.mcgeecompany.com/wp-content/uploads/2010/12/complete-manual.pdf

[CWtheMan]

CWtheMan -
Mmmmmm - a bit confused here. On one hand you seem to be saying that parking on asphalt can damage your tires but you also state that you "park on asphalt". You seem not be following your own advice????

FWIW, I park on plywood boards but I do that because everybody says I should.

I guess I should have worded it differently. I store my trailer in a facility with asphalt parking surfaces. I always put my tires on wooden blocking materials

[bsmith0404]

I'd still like to see some reliable references as to why it is recommended that the tires rest on wood.

Although it doesn't come right out and say that you should park on wood, the article from the Tire Industry Association that I linked eludes to parking on a surface such as wood. It does state
"The storage surface must be firm, clean, well-drained and reasonably level. Do not store tires in contact with black asphalt or other heat absorbent surfaces and do not expose the tires to highly reflective surfaces such as sand or snow."

This is their recommendation for maintaining the best performance of the tire. They make several references to dry locations and reducing moisture. In the quoted paragraph above they say to park on a firm, well drained surface, but stay away from reflective surface such as sand. IMO, most well drained surfaces are going to have a high sand content, dirt and clay retain a lot of moisture. Based on their guidance, I can't think of two many materials that are ideal, but wood seems to be one of the better choices. Yes it will soak up some moisture, but it will also dry out fairly quickly. They do note that it's best to get the tires off the ground completely, but if that isn't an option, I would say wood is the least damaging.

[Wally15]

CWtheMan
Over time, untreated wood, plywood and pressure treated wooden blocks will become saturated with water and remain wet - especially here in the western pacific region over the Fall and Winter months. It would seem that there wouldn't be any significant difference as to the "wetness" between wood and asphalt.

In addition, can you explain how water permeates into the structure of the tire? Does it enter via the nylon threads or whatever else makes up the ingredients of the tire? Are tires not "waterproof"?

I'd still like to see some reliable references as to why it is recommended that the tires rest on wood.

While I don't consider myself an "expert" on tires, I did spend 25 years in tire manufacturing in a variety of engineering and managerial positions.
It's important to keep tires being stored away from standing water as much as possible. Over time, due to age or minor road hazards, small cracks can develop in the tread or sidewall areas, allowing water to get inside to the steel belts or polyester cords (almost no one uses nylon anymore, it "flatspots" too easily).
The steel belts can then rust, leading to tread separation, or the polyester can "wick" the water throughout the tire, shortening tire life. Raise the tires above ground level in storage, wood is fine but anything that isn't dark and doesn't absorb much heat or retain visible water.
It's also important to protect tires from prolonged exposure to direct or reflected sunlight (UV rays). Over time this can break down some of the sidewall ingredients. Anybody ever had a tire where the black sidewall turned a brownish color, or the white sidewall started turning yellow or a tannish color? These are the processing oils in the sidewall leaching to the surface. UV contributes to that (as does tire makers using cheap ingredients). Also makes the sidewall stiff, decreasing tire life (or hairline cracks, leading to water absorption)
If you're cruising down the road at 65 mph, your tires are rotating over 700 rpm. That's a lot of centrifugal force combined with a lot of load.
There are a lot of ingredients in a tire. Natural rubber plus 3 or 4 synthetic rubbers, 3 or 4 different processing oils, 3 or 4 different carbon blacks, and a host of other "minor" ingredients. The average tire has about 10 different "rubbers" in it's construction. It's an amazing manufacturing process, both capital and labor intensive. It's definitely not like making 2 liter Coke bottles.
Hope this helps, the links provided by others are good reference material.
Mike

[ljp]

Thanks for all the feedback.....