View Full Version : Computer placement on cement

May 2nd, 2017, 05:37 PM
I have my retro computing area in the back of my garage. The garage is insulated so stays pretty much like the rest of the house unless it's really or really cold. In any case I am placing 8 computers under a table and booking them all up to a KVM and monitor to play games on them, run software, tinker, etc. my question is - Is it OK for me to put the towers directly on the cement floor or should I get something for them to sit on between the computer and the floor? If so, what?

May 2nd, 2017, 05:47 PM
As long as the concrete stays dry, it's fine. If you tend to get humidity/moisture/creeping damp, then put them up on something. Old places and DIY jobs are bad to omit vapor barrier under the slab, that is often where you run into issues.

May 2nd, 2017, 06:25 PM
Cement is surprisingly good at transmitting moisture from underneath into whatever's sitting on top of it. At least put them up on a wood pallet or something.

May 2nd, 2017, 07:12 PM
If you do set them right on the concrete, don't sit on em or you'll get hemorrhoids. At least that's what the old timers yoosta say.

Some computers were required to have concrete foundations..

But in your case, yes, pallets are your friend. You can get them for free.

May 2nd, 2017, 09:53 PM
Invest in a gallon of concrete sealant. Used quite a bit in garages and cellars to seal off the porous concrete. Relatively inexpensive, easy to apply and it lasts for years.

Agent Orange
May 3rd, 2017, 07:19 AM
Put a few scrap 2 x 4 pieces on the floor and forget about it.

May 3rd, 2017, 08:52 AM
Put a few scrap 2 x 4 pieces on the floor and forget about it.

Or pick up some free pallets. I have a few of those to keep stuff from sitting directly on the garage floor.

May 3rd, 2017, 09:00 AM
Concrete is porous and can outgas enormous amounts of water. Seal the stuff--I speak from experience.

May 3rd, 2017, 09:12 AM
Invest in a gallon of concrete sealant. Used quite a bit in garages and cellars to seal off the porous concrete. Relatively inexpensive, easy to apply and it lasts for years.

Yep very good idea..

Put a few scrap 2 x 4 pieces on the floor and forget about it.

But just make a deck out of 4x4's..

May 3rd, 2017, 10:54 AM
If you decide not to seal the concrete and use wood boards, at least lay down a layer of 6 mil plastic sheeting between the boards and the slab.

May 3rd, 2017, 11:04 AM
The 4 x 4 idea could work well.....

Thinking of putting some plastic down on the floor and then the wood on top of it...the garage doesnt get any water as it is, that should keep the PCs safe.

May 3rd, 2017, 01:57 PM
If you can, try to have an air gap between the gear shelf /pallet and the concrete, so moisture can escape.

May 3rd, 2017, 06:03 PM
I got it setup fairly well as I dont have much clearance under the table....put a plastic sheet down attached to the floor and then a thin wood panel cut to fit the area on top of it with the PCs on there....

DIdnt have enough room for much else.

May 4th, 2017, 04:21 AM
I work for a flooring company.

There are a lot of products you could use, depending on how you want it to look and what your budget is etc.

The cheapest would be concrete sealer as mentioned above, but most sealers are designed to allow the concrete to 'breathe', which means that water vapor can still move out of the concrete.

I would use some type of vinyl product.

The obvious thing would be sheet vinyl, but this might be tricky to get hold of in small quantities unless you can find an off cut.

Another option would be something called 'vinyl plank', which is a vinyl tile in a plank format that looks like wood. You can get in either a plain edge (should be glued down) or interlocking (can be 'floated', ie just laid on the floor with no glue).

A nice economical option would be VCT (Vinyl Composition Tile).
This must be glued down, but it is very economical and hard wearing.
You've probably seen this stuff before - it is often used in supermarkets etc.
It usually comes 45 SqFt to a carton and costs about $1/SqFt. It is very easy to install even for an amateur.

In summary, if you don't want to bother with glue, sheet vinyl or interlocking vinyl plank is what you want.
If you don't mind gluing it down, vinyl plank or VCT.

All of the above products are suitable for installation 'below grade', which basically means below ground level where there may be elevated moisture levels.

Whatever you do, don't buy one of those vinyl floor mats from Staples - they are just regular sheet vinyl marked up 1000%

May 4th, 2017, 07:00 AM
I should probably qualify my "sealer" comment by saying that there are various types of sealers. Acrylic is the cheapest (looks like milk and smells like white glue) and allows a certain amount of concrete breathing. Resin/Epoxy types do a thorough job of sealing. 6 mil PVC sheet is used in the construction industry as a vapor barrier and is very tough. You can sometimes get it in small rolls at big-box stores. Even a cheap tarp from Harbor Freight will do the job--sometimes they're given out as free-with-any-purchase item.

Your big enemy is going to be the temperature. Unless you've got a heated garage, year-long variations in temperature and humidity are going to cause condensation to form inside of your equipment, which left unchecked, could do some damage. Rather than seal your equipment up, you want to encourage air circulation.

May 4th, 2017, 02:18 PM
I didn't mention epoxy sealers for a couple of reasons.
They are expensive, and if you're going to spend that kind of money, you'd be better off with some type of resilient flooring.

The second reason is too technical to post here, but it basically boils down to two things; There are many different coatings that fall into the category of 'epoxy'.
Many epoxy coatings are permeable to moisture (by design) and those that aren't can cause problems when applied to a floor that doesn't already have a moisture barrier.

I'm sure a lot of retail epoxy products claim to perform miracles, but it's just not the best material for this application.

This is an important consideration.
At work, we have two identical machines that are obsolete and in storage waiting for recycling.
One of them has been stored in our climate controlled warehouse, but the other was left in a storage room on bare concrete.

The one that stood on bare concrete has almost rusted through on the bottom, and this is one of the old cases from when they made them properly - the steel is 16 gauge galvanized.

I snapped a photo of the rusted bottom of the machine: