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Inching towards the build...need some slab advice

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#26 Garyth64

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Posted 30 October 2020 - 11:48 AM

"The American Concrete Institute’s (ACI) Committee 302 “Guide for Concrete Floor and Slab Construction” suggests that a vapor barrier may not be necessary where no drainage or soil problems exist and in arid regions where irrigation and heavy sprinkling are not done."



#27 BKBrown

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Posted 30 October 2020 - 11:37 PM

There are potential problems with wood floors on posts also.  Unless they are well above the ground, animals will make homes in the dirt under the floor.  I believe any wood floor should be high enough for a person to crawl under and maintain things, if necessary.  It's a trade-off, either way.  Slabs in unheated buildings around here always sweat when a warm front comes through after a cold snap.  Put your wood floor in with treated wood, ventilate, and screen it, and you probably won't have much problem.

 

Edit: I don't have any problem with ground moisture under my thick slab.  There is rock fill under the slab, and the entire thing sits at the very top of a watershed.  It's all poured in one piece, and a bit thicker in the center.  I can jump up and down on the floor next to a telescope, and the observer sees no vibration in the image at over 200 power.  We actually tried this. 

I had one critter intrusion event under my wood floor observatory, but it was quickly resolved and I never had another incident. One of the things I really like about the slab-less approach is the thermal management. I never had heat retention issues of any kind in seven years.

 

Clear Skies,

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#28 BKBrown

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Posted 31 October 2020 - 12:01 AM

It's interesting discussion, but every case is different based on the users geographic location, weather patterns, and even their local critter population.

I have been in construction for 40 years. I can tell you that a plastic weather barrier over your crushed stone and below your concrete slab is a must in Michigan, but unnecessary in Arizona.

Posting opinions here without first posting your location and normal weather does not help anyone.

Good points. My site is in the rural Virginia Piedmont, mid-Atlantic region. Winters tend to be fairly mild, though wet, and our frost line is 16 inches down. The property is on a long, shallowly sloping hill oriented north-south, it sits within the loop of a major river which is roughly six miles away. Drainage is generally good off of the excellent topsoil. Having cleared two acres, call it 100 yards by 100 yards, to build the observatory and two ranges; the site will get lots of sunlight and breeze due to the lack of trees. Next week we will be dragging the field and planting it in a fast growing wheat to hold the soil, conditions look good for quick germination so we might not be wallowing in mud through the winter. I have tons of wildlife here to include deer, rabbits(!), opossum, skunks, foxes and coyotes, and even a neighborhood bear...so critter control is a consideration. Perhaps this will help further inform the discussion.

 

Cleared area_sc.jpg

 

Clear Skies,

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Edited by BKBrown, 31 October 2020 - 12:06 AM.

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#29 BKBrown

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Posted 31 October 2020 - 12:08 AM

https://dricore.com/...icore-subfloor/ might be worth a look.

Looks cool! Good idea...thanks.

 

Clear Skies,

Brian snoopy2.gif


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#30 Couder

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Posted 31 October 2020 - 08:44 AM

Don't see what you're talking about - I think every response has the location under the name, on the left. Possibly not everybody wants their exact location known, but most have the town and state listed. I had Missouri Ozarks, but just changed it to show my town.



#31 John Fitzgerald

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Posted 31 October 2020 - 08:54 AM

Good points. My site is in the rural Virginia Piedmont, mid-Atlantic region. Winters tend to be fairly mild, though wet, and our frost line is 16 inches down. The property is on a long, shallowly sloping hill oriented north-south, it sits within the loop of a major river which is roughly six miles away. Drainage is generally good off of the excellent topsoil. Having cleared two acres, call it 100 yards by 100 yards, to build the observatory and two ranges; the site will get lots of sunlight and breeze due to the lack of trees. Next week we will be dragging the field and planting it in a fast growing wheat to hold the soil, conditions look good for quick germination so we might not be wallowing in mud through the winter. I have tons of wildlife here to include deer, rabbits(!), opossum, skunks, foxes and coyotes, and even a neighborhood bear...so critter control is a consideration. Perhaps this will help further inform the discussion.

 

attachicon.gifCleared area_sc.jpg

 

Clear Skies,

Brian snoopy2.gif

Brian,  I have tried different kinds of soil holding winter grasses, wheat included, and I found that annual ryegrass gives the best stand and germinated better in late autumn. 


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#32 BKBrown

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Posted 31 October 2020 - 02:20 PM

Thanks for the tip John! waytogo.gif

 

Clear Skies,

Brian snoopy2.gif



#33 jcj380

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Posted 01 November 2020 - 09:03 AM

Annual rye was recommended by a landscaper here for a fast growing fill-in for bare patches in lawns.  Different growing zone and all that, but it does come in fast compared to other grasses.  YMMV.



#34 SimonIRE

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Posted 15 November 2020 - 12:22 PM

I had one critter intrusion event under my wood floor observatory, but it was quickly resolved and I never had another incident. 

 

Hmmm. Possibly similar to mine. The trick is to catch the offending critter, beat it to within an inch of its life and send it back to its mates. Quickly the word gets around...

 

Simples :)




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