If I were doing this, I would use very little portland cement, maybe even none. I would definitely add borax, like 20 Mule Team or 3 Elephants, at about 5% of the weight of the paper. With little or no portland cement the shrinkage will be more, so I would allow for that and plan on a final trim once the block has cured. I would make blocks 4" thick x 18" wide and perhaps 30" long. A final trim to 14.5x24 for a snug fit with few joints. With the relatively smooth edges from trimming there should be a tight mortarless fit and the blocks would be light enough to be installed by one person.
On 4/28/2012 7:40 AM, trendawareness wrote:
Ref. my December '11 post inquiring about slip forming, I'm ready to start insulating my attached garage with PC. This is non-living space and my goal is to reduce the summer and winter temperature extremes in my garage. I live near Cincinnati OH where we have 2 heating days for every 1 cooling day. January's average low is 19F and July's average high is 91F. But rather than worry about potential water damage caused by the run-off from slip forming, I'm leaning toward pouring 4' x 16" blocks the traditional way then placing them between the wall studs. My thinking is that if I pour a 16" wide block, allowing for the usual shrinkage, it should make for a snug fit in the 14.5" space between the studs. My plan is to use the same technique in the overhead attic space between the joists. Here's my questions for the group: (1) What's the suggested PC mix for non-load bearing PC? I'm looking for good R-values, yet bug & termite resistant, blocks. (2) To reduce the amount of cutting and sanding required, I was thinking about pressing the boards between the studs before they're fully dried, say 2-3 days after pouring the mix into the molds. Do you think this method would work? As always, any additional suggestions are welcome! Thanks! Dan PS: One month later my paper (crete-less) weed mats around my shrubs are holding up well. The only weed growth has been in the gaps where the paper mat has pulled back from the landscape blocks. Even after a week of no rain, the mats are damp to the touch. So they're holding in the moisture quite well. ------------------------------------ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/papercreters/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/papercreters/join (Yahoo! ID required) <*> To change settings via email: email@example.com firstname.lastname@example.org <*> To unsubscribe from this group, send an email to: email@example.com <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/ ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2411/4963 - Release Date: 04/27/12