Maintaining and repairing an MT 900 sleeping bag

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Do you own one of our MT 900 sleeping bags and have a question about maintaining and repairing it?

We give you all the necessary information so that you can keep your product for a long time.

First use

What is the rds certification?

The RDS certification - or “Responsible Down Standard” - is a certification that ensures humane treatment of geese and ducks throughout the entire down and feather supply chain.

RDS certified sleeping bag
What does cuin mean?

The fill power is a measure of the down's thermal insulation by "trapping" a certain volume of air. This is expressed in CUIN (cubic inches per ounce).

Consequently, the higher the CUIN number, the greater the loft of the down, the more space it occupies and the more air it traps inside and hence the greater the insulation.

what does cuin mean ?
Why can the feathers of my down sleeping bag escape?

Since down and feathers are extremely fine fibres and are pointed in shape, they easily poke through the seams or lining. It is worth noting that, in any case, the down and feathers inside will inevitably try to get out of the sleeping bag. We choose the tightest possible weave (feather-proof or down-proof tested) to reduce this phenomenon.

This situation can occur especially when the sleeping bag is compressed by folding it in two, or storing it in its bag. The air trapped in the compartments will produce pressure towards the surface, if the feather is in the pointed position ready to come out then the feather will come out, it cannot be avoided.

How to fold up your sleeping bag

Good news, most sleeping bags are now designed to be tidied away easily: no need to fold them carefully to get them into the cover (even for the ultra-compact ones)!
It is particularly true for feather duvets: you must always stuff the sleeping bag into its carry bag or stuff sack, because if you always fold it the same way, the feathers will crease and flatten. And a crushed feather does not provide as much insulation as a feather whose structure is intact.

How to properly engage the zip of the sleeping bag

Before talking about repairs, we are going to talk about how to use your sleeping bag correctly. A lot of customers contact us saying that the zip on their sleeping bag looks broken. Most of the time it is simply an issue with cursor alignment.

Given that the zips are completely open, properly aligning and nesting the sliders is a bit tricky.

Also take the time to close your sleeping bag completely to avoid getting fabric caught in the zip and having to force it.

Zips can also break: if this happens, we recommend you bring your sleeping bag back to the store or ask a seamstress to replace the zip.

Properly engaging the zip of the sleeping bag

What is the temperature rating? 

On all of our sleeping bags, we display the temperature ratings tested by an independent laboratory (AITEX) according to European EN 23537-1 standard of 21/01/2017. The temperature rating is the lower limit at which a person, in a relaxed posture, is generally in thermal equilibrium and feels neither hot nor cold.

What is the limit temperature?

The limit temperature is the temperature limit at which a person who is curled up in their sleeping bag is generally in thermal equilibrium and feels neither hot nor cold.

Quick tip:
Use an insulating mattress to optimise your thermal comfort.

How to avoid feeling cold in your sleeping bag

The temperature rating of the sleeping bags are defined using standardised European tests. But sensitivity to cold also varies from person to person and on the climatic conditions.

How to protect yourself from moisture when sleeping under the stars

It is quite possible to sleep under the stars and stay protected from moisture by using the sleeping overbag. An overbag, also known as a "bivvy bag", is a protective cover that is one size larger than a sleeping bag. You just have to slip inside it with your sleeping bag, along with your mattress if you want, to protect them from the outside elements.
In this way, it can be used to protect your gear and protect you against adverse weather conditions.
It can be used to sleep under the stars or under a tarp.

I have lost my storage bag or my stuff sack

It is possible to lose your storage bag or stuff sack when in the mountains. Not to worry, they are available on the Decathlon website.

Maintaining and repairing an MT 900 sleeping bag

Maintaining your mt 900 sleeping bag


Washing a product that contains feathers is much simpler than it appears, so long as you take a little care: down doesn't go well with water and clumps when it is damp.
As far as possible, avoid washing your feather sleeping bag too often and use a sleeping bag liner.

How to clean a sleeping bag
You will have to fluff up the feathers and down at each stage of the washing process:
- Zip up the sleeping bag and put it in the washing machine
- Add some washing balls or 2 or 3 tennis balls (ideally not brand new balls so that no yellow threads come off).
- Run a cycle at 30°C with your usual washing product (less than the usual quantity) or a special down washing product which preserves its insulating properties
- Rinse twice and set a very delicate spin cycle so that the feathers do not clump together


This advice applies to every type of sleeping bag: it is best to store it uncompressed in the bag provided.
Keeping the sleeping bag compressed in its storage bag can damage the feathers and down, which will lose their fill power. Down does not react well to being compressed for long periods of time.

There are two solutions possible:
- use a storage bag that is bigger than the stuff sack, to preserve the fill power of your sleeping bag,
- hang your sleeping bag on a hanger, like a pair of trousers.

Restoring the water repellent property of your sleeping bag

Over time, the application to make your sleeping bag water repellent may deteriorate. However, it is quite possible to reactivate the water repellency using a re-waterproofing liquid.

Repairing a snag or hole in your sleeping bag

Sometimes, your sleeping bag may have a snag. It is important to repair snags quickly using a patch so that the feathers cannot escape and the thermal insulation of the sleeping bag is preserved.

Choosing to repair it means acting collectively to reduce our impact by extending the life of our products.
The Decathlon store workshops can repair the snag in your sleeping bag. Check out below the service that you can request from your nearest store.
NB: not all stores are equipped to carry out the repair locally. In this case, your product will be sent to a regional workshop and will be kept for a longer period of time before you can recover it.
> To apply the patch, our workshops carry out a heat sealing process.The resulting high-quality patch will extend the lifetime of your sleeping bag and preserve the warranty. However, if you decide to repair your sleeping bag yourself, the product warranty will no longer be valid.

Patching - Decathlon workshop

Repairing a snag or hole in your sleeping bag by yourself

On a trek, you may snag a sleeping bag. The good news is that it can be repaired! Indeed, you can either mend it or patch it so that the tear doesn't get any bigger letting the synthetic fibres or feathers escape.

- You want the repair to be inconspicuous, even pretty?
If the fabric isn't too thin and you know how to sew, take the time to sew up the hole with some thread in a colour that matches that of the outer fabric of the sleeping bag.
When sewing, take care not to go through the other side of the sleeping bag. This would create a thermal bridge and reduce the insulation of the sleeping bag.

- You’re short of time and have no sewing skills?
The sticky repair patch comes to your rescue: cut a round-edged rectangle one or two centimetres larger than the size of the snag, glue it to the clean, flattened fabric and it's done - you're good to go!

Giving a second life to your sleeping bag

Have you stopped using your sleeping bag and are wondering what to do with it?
Instead of throwing it away, don't hesitate to resell it second-hand using the Decathlon Second-hand platform! Fill in all the information about your product online. We will therefore offer you the best sales solutions, then you can drop off your product in the store to finalize the procedure.