[Ferro List] 3 questions for Walter

[dl]

Based on the information, the consideration of water vapor compromising the insulation and 'bridging' as ice in the winter is a valid concern and I think that a decision ought to be based on performance. The wax will greatly slow the water vapor movement in the winter but it will likewise slow the evaporation in the summer for cooling. The material does not degrade from the presence of ice as long as it freezes as vapor application so there is no expansion damage from freezing.

But the only way I can think of to get the information is to wax a spot of 10 - 15x thickness and measure the performance compared to a simular patch with no wax for 5 years or so, measured with a non contact thermometer.

The performance for 2 years sounds excellent, I admire your attention to detail and forthought.

dl




-----Original Message-----
>From: Walter Jeffries <walterj at sugarmtnfarm.com>
>Sent: Feb 27, 2008 9:24 AM
>To: Ferrocement Discussion List <list at ferrocement.net>
>Subject: Re: [Ferro List] 3 questions for Walter
>
>On Feb 27, 2008, at 3:50 AM, Janoahsh wrote:
>> Ahh here we go again.  Thank you for asking this question Keith,
>> Condensation Buildup.
>> I think this problem comes and goes with temperature extremes and  
>> interior
>> use.
>
>One thing that may be helping us is we have a lot of air circulation.  
.......
>setup so that I could have added a large circulating fan in the  
>cathedral ceiling and a muffin fan at the top of each of the three  
>vertical air tubes but that has proved to be unnecessary. I like that  
>as I prefer not having the noise, electrical usage, mechanical system  
>to maintain, etc. Passive is best.
>
>As mentioned in the other post, we are sealing the interior on a high  
>cement parge so that should also help. I have wondered about waxing  
>the entire interior surface but don't think it is necessary. I have  
>yet to actually do any waxing so I may change my mind after we've  
>done that on the bathtub, kitchen counters and the library desk.
>
>Another factor may be that we keep our home fairly cool thus there is  
>less differential.
>
>Temperatures do get down to -45°F in the winter here and we get a lot  
>of wind. -20°F has been our low for the past two years so it has been  
>considerably warmer. Snow depth is about 4' of pack and that helps.
>
>Janosh, where are you located in Alaska? I lived in Fairbanks, Kenai  
>and Anchorage at various times.
>
>One thing you've made me wonder is if outside along the eaves I  
>should put ventilation for the insulating roof lightweight concrete  
>much like conventional construction has. That would let moisture vent  
>if it did get into that layer. Something to ponder.
.......
>I wouldn't put the vent tubes in the walls based on my experience  
>with them in our old farm house. I didn't do that but I did measure  
>the temperature with probes in lots of places. The air tubes can  
>create cool spots if you do it that way. Instead, on the new tiny  
>cottage I brought all the air in along the floor at the base of  
>walls. We also have outgoing air tubes that drain away the coldest  
>air in the cottage from the lowest points. This lets the cottage  
>breath. Our cottage is so tight that it is hard to open and close the  
>door if you have all the vents closed. The vents are necessary,  
>otherwise when you open and close the door the wood stove will puff  
>back - ick!
>
>
>Cheers,
>
>Walter Jeffries
>Sugar Mountain Farm LLC
>Orange, Vermont