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Waterproofing & Rug Breathability

Posted by Caribu Team on July 25, 2019

No horse rug is ever 100% Waterproof. This is because all rugs contain stitching, webbing & fastenings that can not always be tape seamed to prevent water penetration.

Synthetic denier gets its waterproofing from the membrane that lines the underside of the fabric - not from the fabric itself. Waterproof synthetic rugs use a chemically treated membrane, underneath the denier, to prevent water passing through the fibres, while allowing air to pass in between the fibres. Synthetic rugs are the best rug for keeping your horse dry and outperform canvas rugs in this regard.

Caribu Synthetic Denier Horse Rug Waterproof Fabric Rating - exceeds 3000mm for waterproofing - more than twice the minimum rating

Caribu Synthetic Denier Horse Rug Breathability Rating - exceed 3000g/m2/24hrs for maximum comfort.

Horse Rug Waterproof Membranes

A waterproof membrane is applied to the underside of the fabric to provide the waterproof feature of the horse rug. The quality of this membrane is the single biggest differential between cheap and expensive horse rugs.

Many manufacturers sacrifice the quality of the membrane with a cheap alternative - this creates a rug that leaks under heavy rain, or the membrane starts breaking down quickly when in use and the membrane starts to peel away from the fabric. Its also very common to see waterproof deniers that do not have breathability built into the membrane - its simply waterproof. 

What are taped seams and heat sealing?

On waterproof deniers its the fabric that is waterproof, not the seams and fittings. Obviously, sewing puts 1000's of little holes in the fabric. To address this, heat sealed waterproofing tape is applied on the inside of the fabric over the joins in the fabric. This is before any internal lining is added.

Tape sealing doesn't create a 100% waterproof seam, it simply slows water entry down. We use tape on all our side seams and on the stitching behind belly surcingles.

There are some places that can not be tape sealed - behind chest straps, rear leg strap D Rings and tail flap joins. With chest straps to achieve the best strength, chest fittings are attached to the rugs after the internal lining. The chest strap fittings need to be sewn through all layers. Same with D rings used for leg straps, they are stitched through all layers of fabric (including through the rear surcingle binding).

Tail flaps are a little more complicated. It's just not possible to tape seal a tail flap attachment as you can not gain access to the underside of the stitching. Tail flaps are a separate panel of fabric attached to the horse rug. If you look at a tail flap attachment you will notice its actually 8 layers of fabric thick (4 layers of binding, 2 layers of the waterproof denier and 2 layers of linings) Unlike other areas on the rug, water runs off the rear of the rug and catches/pools on the tail flap bindings. On initial use you will find that the tail flap seam will let some moisture through - the stitching thread we use needs to settle and swell with initial use, and fill the sewing holes, slowing water entry. Most users find that within a few uses and moisture issues reduce as the pours in the fabric swell around the stitching.

Water entry around the tail flap is unavoidable, You will notice that we use very large tail flaps that include a large arc of attachment/seam along the top of the tail flap. This is aimed at covering under rugs as much as possible. Many other manufacturers will use a smaller tail flap with a much much narrower join to the rug, which allows significantly more water to enter down the sides of the tail flap. On a correctly fitting rug, the tail flap seam should be situated below the top of the horses tail.

^ Heat sealed taping on internal seams to reduce water entry

How can I check if my denier horse rug is still waterproof or breathable?

The number one reason people think their rugs is leaking is that in wet conditions non-breathable denier will breathe.

To check to waterproof is easy. The best way to check your rug is waterproof is to use a sink or large tub, lay the rug over the top and create a small indent with the denier - ensure you choose an area of the rug with no fittings. Then pour a glass or two of water into the indent and allow the water to pool. The denier should hold the water and not allow any seepage to the inside.

Your synthetic denier gets its waterproofing from the membrane that lines the underside of the fabric - not from the fabric itself. Once the membrane is damaged, you cant reseal like you can with canvas.

The top 2 reasons people mistakenly think their rug is leaking;

1 - Reduced breathability, or sweating.

If you have an unlined rain sheet, you can see the underside of the denier through the mesh lining. If you hold the rug up to the light and look up from the underside – you will see the thousands of little pins holes of light – these are the waterproof pores in the fabric that give the rug its breathability. The waterproof membrane ensures the holes are smaller than a water molecule – so water can not pass through the rug. 

Denier fabrics can be made breathable via using ultra tough hi-tech fabrics which are then coated with a micro-porous formula making the fabric completely waterproof and breathable. This means that the outer fabric will protect your horse from the rain and elements while still allowing sweat or condensation produced by your horse's heat to escape through.

The waterproof membrane also needs to be breathable otherwise your horse will overheat quickly. Cheap turnouts often use membranes that have a non-breathable membrane.

For any turnout rug to keep your horse comfortable on the inside, both the outer fabric and the lining should also be breathable - because even in cold conditions, your horse will perspire and if a garment does not have sufficient breathability, the moisture from perspiration, in combination with the difference in outside/inside air temperature, will build up as condensation on the inside of the rug.

This problem is exaggerated if your horse does some sudden activity. A quick 30sec gallop across a paddock can cause an average horse to perspire very quickly and the rainsheet just doesn't offer enough breathability for the horse to cool down quickly

Keep in mind that regardless of the rugs breathability rating - in wet conditions, it will be reduced to almost zero. Water covers the rug's fabric pores. This can cause condensation to accumulate on the inside of the rug. This extra moisture on the inside may also give the illusion that the garment is leaking water in from the outside when in reality it is your horse's perspiration and condensation causing the moisture. This is more common when using rain sheets, especially in open neck rain sheets, where water enters in around the neckline and then condenses from body warmth

Most Winter Fill Synthetic Turnout Neck Rugs have a fill or lining of up to 300grams and this alleviates this problem, as it assists the rug to breathe and keeps the horse's excess perspiration off the horse's coat. If you are using an unlined rainsheet in humid, extended wet or cold conditions – you may need to use in conjunction with a light cotton under-rug or similar with good moisture wicking properties. The horse's perspiration and condensation need to be transported away from their skin.

It's much like us wearing a raincoat against our bare skin - with your body heat and perspiration, you will soon be very clammy under your raincoat and any moisture that enters via a neckline etc – will condense under the raincoat. You will end up very damp in a short span of time. However, if you wear a T-shirt you will help alleviate the problem.

Never underestimate how much condensation will accumulate under the rug in a short span of time. A horse can perspire up to 1 litre per hour.

2 - Wicking

Over time, water will wick its way up the internal lining of a horse rug. Water gathers on the drip lines and bindings of the horse rug and the internal linings will slowly suck up moisture via a natural capillary action. In most cases, this happens slowly and doesn't have much of an impact.

However, this process is rapidly accelerated when you have an under rug that is hanging out from under your rainsheet. You only need an under rug hanging out a few mm from the top rug and this fabric acts a bit like a sponge sucking up the rain as it's coming off the outer rainsheet and you can end up with both the under the rug and the rainsheet lining being wet. You don’t need a lot of rain for this to happen, its more about the length of time involved. i.e. the 5mm of rain that falls in 10mins won't have much of an effect. But 5mm over 6hrs allows more time for the capillary action and for water to wick its way in.

Features of Caribu Turnouts that Improve Waterproofing

  • We only use Premium 1200 Denier or 1680 Denier fabrics. 
  • We use extra wide fabric for construction - which allows us to deliver generous drops even in the bigger sizes. (as an example size 6'0 has a generous 106cm drop up to a 7’0 with a 115cm drop.)
  • You will notice we also use a continuous run of fabric in the neck and body of the combo - no joins or seams in the neckline or back seam to let water in! The continuous neckline also helps to reduce mane rubbing.

To ensure you get a long life from your waterproof denier horse rug, take a few precautions

  • Firstly, we do not recommend machine washing synthetic rugs at all.

    • Never use warm or hot water on a synthetic denier. You will very easily damage the rubber like a waterproof membrane on the underside of the fabric - making it useless.
    • We recommend you don't use detergents or any type of chemical on synthetic waterproof rugs as this can damage the waterproofing membrane.
    • Washing machines, especially top loaders which, with high agitation, can damage the waterproof membrane linings from excessive stretching.
    • We suggest you hand wash them in cold water or wipe off with a damp cloth or sponge. Make sure you never scrub.
    • Line dry only - never use a tumble dryer.

    To help get the best life from your waterproof denier, take a few precautions;

    • Never spray a high-pressure hose at your horse rug - you will damage the small pores allowing water to enter immediately.
    • Never use a harsh bristled brush to scrub the outer denier, you can spike the membrane
    • Never wash your waterproof rugs in a hot wash - cold water hand wash only.
    • Never use additives like Tea Tree Oil or Eucalyptus oil etc on your rugs or in the wash - they can affect the membrane lining
    • Never put a rug away damp or sweaty for long periods of time. Mould and mildew will eat away at the membrane over time.
    • UV will eventually affect the lining over a long period of time. When rugs are not being used, avoid leaving them out on rails in direct sun for days or weeks at a time.
    • Before storing your rug away, ensure it is dry and at room temperature. Don't take directly from a warm sunny clothesline and seal away, as this can be detrimental to the waterproofing membrane. Allow the rug to cool down and air at room temperature for a few hours before packing away.

    Why synthetic horse rugs need more care:

    • The polymer membrane lining, which gives the rug it's waterproofing, is similar to a rubber compound. It has an inherent moisture content which varies with environmental conditions like humidity etc. Waterproofing eventually fails in a rug when the lining ages and the polymer dries out and becomes brittle. Storing the rug away for long, extended periods, can accelerate the breakdown of the membrane. The rug needs to be aired from time to time to allow it to 'breath' & ensure the polymer lining doesn't dry out excessively. Rugs that get used infrequently are usually the ones that have the shortest membrane life because they either dry out or grow mould.
    • Some horses perspiration can be more acidic than others, depending on diet and this can shorten the life of the membrane.
      • Please click the following link for our full range of Waterproof Turnout Rugs.

Canvas Horse Rugs Care Guide

Not all canvas is created equally and just because a rug its called canvas - don't always expect it to be waterproof. The fabric construction and waterproofing process can vary greatly.

Canvas can range from a 100% cotton blend, which is cool and breathable, to 100% Polyester which is very strong but also can be hot. You will see a huge range of Canvas rugs that fall between the two extremes and their performance will vary significantly. The type of weave and machine the fabric is manufactured on also plays a huge part in the success of the rugs ability to perform well.

Canvas comes in different thickness or weight, often from 11oz up to 22oz. Obviously the heavier the canvas - the longer the potential waterproofing.

Corespun Canvas Horse Rugs is gaining popularity as the technology to create the fabric comes down

What are the benefits of Core Spun Canvas? Numerous! A traditional canvas thread comprises of a blend of numerous fibres grouped and spun together to create a single thread, (At a simple level think of braiding your hair!) which is then woven into a canvas. Core-Spun canvas is made from a much more intensive process. Each thread consists of a strong central core of polyester, which is then tightly entwined in a 100% Cotton outer layer. This creates a very strong dense fabric that is considerably lighter and stronger but achieves the same performance as a much heavier traditional canvas otherwise would. The tighter weave also helps to improve waterproofing as the cotton around the core expands and gives better waterproofing while still maintaining excellent breathability.

Canvas horse rug fiber image

Canvas Waterproofing

With Canvas, it's important to understand how canvas has been waterproofed. There are three different processes used to the waterproof canvas.

1) Wax Coated (90% of imported Canvas)
2) Immersion Treated (Caribu Canvas)
3) Immersion Forced (Dyna Proofed)

Immersion Forced. The good old fashioned Canvas, that some of us remember from days of old, is treated via an Immersion forced process. In simple terms, the fabric is submerged in a waterproofing agent and the agent is forced deep into the fabric. This is the best process for treating the canvas because the fabric is scraped or torn, water won't wick through the fabric. However, It is also very expensive in today's market.

Immersion Treated. Similar to Immersion forced canvas. The fabric is submerged in a waterproofing agent. Both sides of the canvas are treated and it relies on the absorption of the agent into the fabric. This process is much better than wax coating as it takes much longer to degrade.

Wax Coated waterproofing process is where the fabric is simply sprayed with a light wax coating. These rugs are at best, only light shower proof, and it's how most of the canvas rugs from overseas have been treated. We see many marketing waxes sprayed rugs as 100% waterproof - you will be disappointed. The wax coating begins degrading extremely quickly when exposed to the elements.

Our canvas is proofed via an immersion treatment. (not wax coated) and delivers improved performance compared to the wax coated canvas which is flooding the market. We quote our canvas rugs as being Showerproof. They will outperform wax coated canvas and provide good protection. In our mind to call a rug waterproof, it has to be able to withstand extended or heavy wet weather and still keep your horses dry. (something our synthetic rugs and combos do very well) Any Canvas slowly absorbs the water over time, getting heavier, until it reaches the underside of the canvas. Water will also enter via stitching seams, over time the stitching threads will expand and general grit will tend to seal the stitching along seams, however, there is always the risk of water entry, especially in initial use. We see many retailers advertising their wax-coated rugs as 100% waterproof - which is misleading. Likewise, a heavier canvas rug will provide better longer term waterproofing: ie: a 20oz canvas will outperform a 16oz canvas.

No Canvas rug is 100% waterproof. While the fabric may provide good waterproofing, water will initially enter via stitching lines, along seams, necklines and around fittings. Canvas rugs use are sewn using a specially developed cotton covered nylon thread. This is designed to swell when wet, to completely fill the stitch holes.

A high wool blend lining (not just felt) creates a membrane between the canvas and horses coat to extend water penetration. Canvas will absorb moisture from exposure to rain and from condensation under the rug. If you use canvas in wet conditions, you will need to remove canvas regularly and allow to dry out completely. During heavy rain or long periods of light rain, the canvas will eventually 'wet out' and the fabric will become saturated. This is part of the breathability of the canvas. Provided you have a wool layer or wool lining between the canvas and the horse, the horse should remain dry for longer periods (even thou placing your hands between the wool and canvas it may appear wet) The wool will repel the moisture and keep it at bay between the wool and inner canvas. As soon as the rain stops, the horse's body heat will start drying the rug.

Lined or Unlined Canvas?

Unlined canvas rugs are great for warmer days and cooler nights, but horses in unlined canvas rugs often have high moisture transfer during very heavy rain or extended hours of rain, due to the difference in the horse's body heat and the cool canvas. Wool lined Canvas helps reduce this problem and creates a buffer to trap the moisture. Like touching the inside of a tent when it's raining, the tent will start to leak at the point you touched it. A similar process happens where the rug makes contact with the horse, creating moisture transfer onto your horse. Amount of transfer depends on many factors like air temperature, humidity and body heat.

During heavy rain or long periods of light rain, the canvas will eventually 'wet out' and the fabric will become saturated. This is part of the breathability of the canvas. Provided you have a wool layer or wool lining between the canvas and the horse, the horse should remain dry for longer periods (even thou placing your hands between the wool and canvas it may appear wet) The wool will repel the moisture and keep it at bay between the wool and inner canvas. As soon as the rain stops, the horse's body heat will start drying the rug.

Canvas is ideal in many situations, it provides superior strength to synthetic rugs, is very breathable and is ideal for short bursts of wet weather protection.

We suggest for the best performance that you apply a waterproofing treatment to your rug after the first 12mths to increase its life.

To ensure the long life and durability of your canvas rug - please follow these instructions:

  1. Prior to using we suggest you thoroughly wet the canvas with a light hose and let the rug dry fully in the sun. This is necessary to allow the fabric to settle and stitching to swell. If you fail to do this you may find your rug absorbs excessive water in the initial exposure to rain. Store away only when completely dry - this will avoid disappointment when you next get your rug out again and find it very mouldy! Do not use a high-pressure nozzle to wet your rug as the high pressure could compromise the waterproofing.

  2. Never scrub the canvas - to remove dirt use a damp cloth or try brushing the fabric with a soft brush when any dirt has dried. Do not use soaps, detergents or other liquid cleaners.

  3. Remove any mildew as it appears, and allow the rug plenty of sun exposure afterwards.

  4. No Canvas rug is 100% waterproof - the waterproofing process is designed to repel showers & light rain & won't stand up to heavy or prolonged weather, as water will slowly seep thru the fabric. The thickness and tight weave help to slow the seeping process. With exposure to heavy or prolonged periods of rain - you will need to remove canvas regularly and allow to dry out completely.

  5. Our Canvas is 100% Cotton - please ensure before storing your rug away it is 100% dry - as any moisture in the fabric will cause mildew and deteriorate the canvas during storage.

    The waterproofing agent used on canvas breaks down with exposure and you may need to apply a waterproof coating every 6-12 months to ensure the waterproofness of the canvas. Much depends on the weave and fabric composition. Please click the following link for our full range of Canvas Horse Rugs.

What is the difference between 600, 1200, & 1680 Denier Horse Rugs?

At Caribu we only produce predominantly 1200Denier Rugs. 1200 Denier uses double the thread weave over a 600D fabric. 1200D offers far superior strength and durability and will far outlast a 600D rug. There is very little difference in Breathability, Insulation, Waterproofing or weight - what you do get is the added strength & life.

Many manufactured have reverted to 600D fabrics because they are cheaper to produce.

How much horse rug filling is enough to generate warmth?

Understanding how a poly-fill lining works can go a long way to ensuring your horses comfort this winter. Polyfill is very similar to the poly fibre that you get inside a pillow (much like hobby fill) Polyfill used in horse rugs comes in long flat lengths of a roll. The lining works much like your roofing insulation - it traps heat in the air pockets in the polyfill lining and slows down the radiant heat out of the rug and away from the horse.

We use either 200gram and 300grams of polyfill in our "Alpine' range of winter horse rugs. So a rug advertised with 300grams of polyfill means for every square meter of laid out polyfill lining - it will weigh 300grams.

A good analogy is to think of a cotton ball you may have in your medicine cabinet. When you take it out of the packet - it is relatively compact. (ie actually quite close to what 300grams of polyfill is like inside a horse rug.) It would have good insulation properties as there are lots of tight air spaces to act as insulators in the body of the cotton ball. If you then start pulling it apart and spreading it to make it thinner, you start losing those insulated air pockets as the cotton ball opens up and thins out.

The actual insulation performance between a good 200gr vs a 300gram isn't as dramatic as most people like to think. It does come down to personal choice and your horse, as to how much polyfill you should opt for in your horse rugs. It also depends on how long your horse's coat is - or how short you wish to keep it. Also depends how early or late in the season you start and stop rugging. Some horses are 'hotter' than others and some feel the cold more (young and older horses especially)

Many people find 200grams isn't enough in the middle of winter and they need to use multiple under rugs to get the desired level of insulation. Others prefer to use 300gsm and only layer a lighter rug underneath (or use no under rugs at all). It's much quicker to use one 300gr rug than a 200gr and multiple under rugs. That's a lot of buckles, surcingles and leg straps to do up/undo every day!