Placing cargo bag directly on roof.

[Conor]

Hi guys,

Now that I need to haul a bunch of worthless crap back to Ireland. I have considered using the roof of the wagon.

I've settled on a roof bag. Question is, while I intend on using a rubber protective mat, I am wondering if placing the bag directly on the roof will damage the structure, i.e. push it inwards or something?

This seems to represent good value @ £41 for 425 Litres and can be compact when not needed.

Admittedly this one does show cross bars being used, but I think you may be able to do without. The second one does not show cross bars.

EDIT, Links:

• AUPERTO Waterproof Car Top Carrier - 425 Ltr - £41
• Sailnovo Waterproof Car Top Carrier - 450 Ltr - £58

 

[Blobcat]

It will scratch it if anything gets underneath it

 

[Conor]

It will scratch it if anything gets underneath it

Fair, hoping the rubber mat would help with that.

 

[Blobcat]

Fair, hoping the rubber mat would help with that.

Yes, but dust, grit and general detritus will get under it when driving and the rubber mat will just work as a scouring pad...

 

[rorywquin]

Don't do it. You will be sorry.

 

[DeeEmm]

I toured the north coast of Scotland in September/October a couple of years back and toured Ireland for 8 days with a boot bag on the boot of my MX-5.
The weather was horrendous on occasions with heavy rain etc.
The boot bag I used was from this company https://boot-bag.com/

It came with a perforated rubber mat which the bag sat on, no issues whatsoever, no marks at all, and the items stayed dry to boot (I'll get my coat).

 

[bembo449]

its an awkward one Conor , as you will be going quite a distance , yes ?

 

[V6Matty]

Find a cheep set of roof bars and don’t worry about it after, you could even sell the bars on again and likely make your money back

 

[Tony Dyson]

^+1 I think you'll find the reason why the boot bag is fitted to roof bars is something to do with the construction and use of a vehicle, perhaps @Craiglxviii will know something of this he appears knowledgeable on these matters?

I knew of a company who had constructed roof racks on a fleet of vans fixed through the roof onto the supporting framework below and after a motorway accident they and the driver were prosecuted for insecure load and construction & use charges?

 

[Craiglxviii]

^+1 I think you'll find the reason why the boot bag is fitted to roof bars is something to do with the construction and use of a vehicle, perhaps @Craiglxviii will know something of this he appears knowledgeable on these matters?

I knew of a company who had constructed roof racks on a fleet of vans fixed through the roof onto the supporting framework below and after a motorway accident they and the driver were prosecuted for insecure load and construction & use charges?

Sure.

The car roof forms the upper part of the strength girder. The roof is made of a number of beams held together with one or more panels, sometimes the panel and beam/S are formed in the same part/s. Basically, load is transmitted to the A B C pillars to the roof, and laterally/ longitudinally across to the opposing side of the girder.

Roof boxes are fixed to bars which mount directly on the roof beams or cantrails that run along the side edge of the car. Thus any load placed in a roof box is transmitted straight into the body strength girder.

A load that is placed on the roof metal is sat on a sheet of steel between 0.6- 0.9mm thick in a typical car. It’s like walking on an old corrugated roof- you need roof ladders to spread the weight. Same principle- here you have all the load sat directly on thin steel panelling, while driving, so it’s bouncing up and down too.

Never mind the vehicle safety aspects, the roof metal will end up looking like the surface of the moon.

 

[Craiglxviii]

Added- do not use without roof bars. You’ll dish the roof in.

 

[LostKiwi]

If you have the rails running along the car (as most estates do) you can buy a couple of bits of 2x2 wood to use as roof bars and firmly lash them down. Took some stuff 500 miles to France like that with no problems.
Don't use bungees to lash as they aren't strong enough - ratchet straps are ideal.

 

[Wighty]

Put your name and address in the roof bag just in case

 

[John Laidlaw]

There’s some really cheap but reasonable roof bars on the eBay and also roofboxes direct, not worth the risk IMO

 

[Blobcat]

If you have the rails running along the car (as most estates do) you can buy a couple of bits of 2x2 wood to use as roof bars and firmly lash them down. Took some stuff 500 miles to France like that with no problems.
Don't use bungees to lash as they aren't strong enough - ratchet straps are ideal.

Just don't tighten the ratchet straps so tight they pull the roof bars out...

 

[mioba]

Put your name and address in the roof bag just in case

No don’t do that. You will be easy to find when the load goes flying across the motorway and done for travelling with an unsecured load.

 

[mioba]

No don’t do that. You will be easy to find when the load goes flying across the motorway and done for travelling with an unsecured load.

Second thoughts put your mother in laws details on.

 

[Jim2]

I'd definitely be putting crossbars on to the longitudinal rails, and letting them carry the load....lot's of good advice given above about lashing it down etc, but one more bit..after about a half hours drive, pull in somewhere and re-tension the ratchet straps,,,and do it periodically throughout the trip. You'd be surprised at how loose they can get. It goes without saying that in terms of the Nr of straps, the more the merrier ! Good Luck, anf Safe Journey .

 

[Conor]

Thanks guys some great advice here.

A had always intended on using lashing with ratchet vs bungee.

The cross bars are definitely a good shout and make great sense.