Mattress Underlayment

[patbratton]

I have looked around the internet and have decided to purchase a mattress underlayment from Sailrite. Before I do I would appreciate knowing what others have used to allow circulation under bedding to mitigate mold and dampness. All suggestions are welcomed.
Moisture Prevention Underliner 60" x 90"

 

[jssailem]

After my first week on the boat up here in the PacificNW I went to Fisheries Supply and purchased “HyperVent”. It is a 3/4” layer the separates the mattress from the boat. Like floating on air.

Hot moist body air passes through the mattress and out to the sides. Your mattress remains dry and comfortable.

Best product I have found for a reasonable cost.

 

[dlochner]

We also used hypervent. Seems to work well.

Apparently it was originally invented for use in landscaping to allow drainage and block sediment from flowing into a drain field.

Hypervent Condensation Prevention Matting

Plain and simple, a differential between the inside and outside temperature can cause condensation. A favorite place for condensation is under mattresses, bunk pads and cushions. Ask any boater and they'll tell you stories of damage caused by condensation

www.defender.com

 

[PaulK]

We used the Froli plastic spring system on our previous boat. Adjusted easily to fit the awkward space (e.g. in the V-berth) and was simple to install. Worked well to keep mold & any odors away and made the cushions much more comfortable to sleep on.

 

[ggrizzard]

for Hypervent. My buddy boat and I have used it for years.
We've never seen any condensation.
Just make sure to put the 'fabric' side UP!

 

[Crusty Ol Salt]

Excellent topic

 

[Ralph Johnstone]

Before I do I would appreciate knowing what others have used to allow circulation under bedding to mitigate mold and dampness

There is no air circulation under any of our mattresses and everything is bone dry and dusty under there. Always has been and always will.

The original Hunter mattresses installed on our 1999 H-310, first had their interior foam rolled in polyethylene film and then evacuated (as I did when installing harder foam) with a vacuum cleaner. The foam rubber shrivels down to something about a 1/4" thick which easily slips inside the zippered mattress cover. The plastic slowly leaks and fills with air to its original thickness again. Supposedly, this is how foam filled mattresses are made. The thin poly acts as a vapor barrier. Think of the vapor barrier in an outside wall in a house and how it works which I'm sure, requires no explanation. But for the naysayers :

I didn't believe those air circulators when I first saw them years ago and can't believe they're still being sold. The only application I can see for them is for a spring coil mattress and even then, I would think a waterproof mattress cover would achieve better results by stopping the moisture at the top level before it has a chance to get to the cold bottom.

 

[Project_Mayhem]

I spotted this the other day and instantly thought of boat mattresses and flooring

 

[dlochner]

There is no air circulation under any of our mattresses and everything is bone dry and dusty under there. Always has been and always will.

The original Hunter mattresses installed on our 1999 H-310, first had their interior foam rolled in polyethylene film and then evacuated (as I did when installing harder foam) with a vacuum cleaner. The foam rubber shrivels down to something about a 1/4" thick which easily slips inside the zippered mattress cover. The plastic slowly leaks and fills with air to its original thickness again. Supposedly, this is how foam filled mattresses are made. The thin poly acts as a vapor barrier. Think of the vapor barrier in an outside wall in a house and how it works which I'm sure, requires no explanation. But for the naysayers :

View attachment 212353

I didn't believe those air circulators when I first saw them years ago and can't believe they're still being sold. The only application I can see for them is for a spring coil mattress and even then, I would think a waterproof mattress cover would achieve better results by stopping the moisture at the top level before it has a chance to get to the cold bottom.

The thin plastic film and vacuum cleaner works. I used it to replace the foam on my cushions. Sailrite.com has a video on how to do this.

If the film remains intact during the install and the film is left, it will provide a vapor barrier. However, this is not always the case, some cushion makers remove the film which removes the vapor barrier.

Another variable to consider is the frequency in which the cushion is used for sleeping. Weekends only, with good air flow during the week, (covers off) the cushions can probably dry out enough in most climates to not be concerned. Living aboard for extended periods with the covers left on? It is probably a good idea to provide adequate ventilation.

Then there is the bedding, a nice absorbent mattress pad will stop a lot of the moisture from reaching the mattress. No mattress pad or a thin one, the mattress will absorb moisture.

As with most thing sailing and boating there are multiple factors to consider and each case will be some what unique. We have the Hypervent, and we're happy with it.

 

[Ralph Johnstone]

After looking at @patbratton 's underlayment from Sailrite, I wondered how the price compared to poly film as a vapour barrier :

This supplied enough material for ONE mattress.

Looking at the poly vapour barrier :

I would think 10 yards would be enough for a whole boatload of mattresses. Aw, what the heck, go crazy and use one roll at $17.00 per mattress, it's still cheaper than $158.63 per mattress and far superior at that. Stop the moisture at the source rather than letting it travel through the mattress and condense on the cold bottom and then hoping it will dry out the next day.

Mind you, looking at @dlochner 's note re the Sailrite video on packing foam into cushion covers led me to their "cushion wrap silk film" which would be much easier than begging dry cleaning bags from our local dry cleaner as I did. They worked just as well but more difficult to install.

 

[Hello Below]

Stop the moisture at the source rather than letting it travel through the mattress and condense on the cold bottom and then hoping it will dry out the next day.

We had used Hypervent under our boat bed mattresses for 15 years and still experience dampness under the mattresses. Three years ago we splurged and spent $20 on a cover similar to this one. Quick as a flash the condensation under the mattresses disappeared.
109,394 people can’t be wrong. Can they?
Five Sided Mattress Protector

 

[Ralph Johnstone]

109,394 people can’t be wrong. Can they?

109,393 people maybe, but 109,394 is stretching it somewhat. But then again, I'm from Missouri .

Three years ago we splurged and spent $20 on a cover similar to this one. Quick as a flash the condensation under the mattresses disappeared.

$26.84 sure beats the hell out of the Sailrite job at $158.63 ! And the above Linenspa cover is based on sound logic. If the mattress isn't already torn apart, that's the way I would go. Mind you, if you are working on the mattress, you'd be using the wrap silk film (or dry cleaning bags) to insert the foam and there's your built in vapour barrier.

 

[Alan K]

Still happy with HyperVent after about 12 years. We sail weekends and for a few weeks each season.

 

[DannyS]

After looking at @patbratton 's underlayment from Sailrite, I wondered how the price compared to poly film as a vapour barrier :
View attachment 212361

This supplied enough material for ONE mattress.

Looking at the poly vapour barrier :

View attachment 212362

I would think 10 yards would be enough for a whole boatload of mattresses. Aw, what the heck, go crazy and use one roll at $17.00 per mattress, it's still cheaper than $158.63 per mattress and far superior at that. Stop the moisture at the source rather than letting it travel through the mattress and condense on the cold bottom and then hoping it will dry out the next day.

Mind you, looking at @dlochner 's note re the Sailrite video on packing foam into cushion covers led me to their "cushion wrap silk film" which would be much easier than begging dry cleaning bags from our local dry cleaner as I did. They worked just as well but more difficult to install.

Lightweight plastic painters drop cloths work the same as the Sailrite plastic silk and can be found at most hardware stores. I had half a roll leftover from a painting project so I used it after washing the cushion covers and it worked perfectly.

HUSKY 9 ft. x 12 ft. 0.7 mil Drop Cloth (3-Pack) DCHK-07-3-12 - The Home Depot

HUSKY 9 ft. x 12 ft. Drop Cloths feature plastic construction and are designed to cover surfaces and help provide protection to floor coverings and furniture during painting applications. Use to help guard against water, dust, dirt and paint overspray. Can also be used as a temporary cover for...

www.homedepot.com

 

[Ralph Johnstone]

Lightweight plastic painters drop cloths work the same as the Sailrite plastic silk and can be found at most hardware stores.

Did they produce any crinkling sound when you lay on them ?

 

[chuckwayne]

we put in the froli system on Escape and it's fantastic - without taking sides in the vapor debate, we've never had moisture under the mattress since installing the froli and it's wonderful to sleep on- just like a spring mattress under the foam

 

[dlochner]

Did they produce any crinkling sound when you lay on them ?

Not if you buy the right kind. My canvass guy uses the cheap plastic sheeting that he can buy by the roll. It is only a mil or two thicker than the Sailrite stuff.