Foam

[Chris Smith]

There are several choices when it comes to foam. I prefer to use Dow blue board. This is an extruded form of polystyrene. This means that the entire board is made of one continuous piece of foam. This foam of very durable and will last many years. Blue board comes in several forms and it is important to get the right one. The best is "square edge" and not the "score board". Square edge foam is a solid sheet of foam. The score board has scores top and bottom to make it easy to break. The scores are at a standard stud layout and intended for insulation in walls. The scores make it easy for contractors to break and install.

The other type of foam is EPS or expanded polystyrene which is thousands of small pellets that are expanded into a form. The EPS foam is not nearly as strong as extruded and will break down easily. Roots of aggressive plants will actually grow into the foam. I have one of these sheets in my system and it is now dedicated to mint as the roots are growing throughout the foam.

[David Hart]

Hi Chris, you are correct...the 'pounds' refer to the density.  It's the weight  "per cubic foot".

I've tried the 2, 2 1/2 and the 3 pound. I wouldn't use anything less then the 2 1/2 pound.

Sorry, I have no spec sheets on the foams. I can say, with the 3 pd, it's suprising how difficult it is to push your fingernail into it. It's very dense....also suprisngly heavey. A full sheet,  2 inches thick,  weighs 16 pounds. Even a 2 x 4 ft raft is 4 pounds, empty.

Here in the mainland....the 2 1/2 and the 3 are costing about the same as the dow blueboards. Of course, like you said..... buying dirrect from the manufacture, and buying in volume will make a differance

[Karen Swanberg]

Regarding how to drill the holes in the foam, I made a video of how I've been making my rafts, using 2" foam:

 

[DJ Bisson Jr]

WOW!! Karen you made it look really easy. Thanks for sharing. My question is do you have to paint the board or is a preference, I am going to use the Dow blue if that makes a difference?  What is the reasons for this. Thanks again.

[David Hart]

Nice video Karen....

Sometimes, I wasn't going deep enough on the 1 st side. So, I took the pilot bit out of the hole saw and replaced it with a slightly longer one. 

In order to make good potting soil go a little further....I've been saving the 'plugs' and using them in the bottom of potted plants.

[Karen Swanberg]

DJ, polystyrene will break down in UV light. The paint prevents that, making the rafts last years longer.

The dow blueboard is the preference. I just couldn't get it. I think my yellow ones are identical, except the blue dye. The MSDS's are the same for mine and the blue board.

 

It's the pink stuff you have to avoid.

[Nigel Clement]

Karen, thank you very much for your video contribution.

[DJ Bisson Jr]

Karen thanks again. What kind of paint do you use? Or does it matter, just an outdoor latex paint?

Karen Swanberg said:

DJ, polystyrene will break down in UV light. The paint prevents that, making the rafts last years longer.

The dow blueboard is the preference. I just couldn't get it. I think my yellow ones are identical, except the blue dye. The MSDS's are the same for mine and the blue board.

 

It's the pink stuff you have to avoid.

[Joe Bifano]

I was just quoted for a 2" EPS board 24"x48" $8.54 for 1.5 lb. That is $34.16 for a 4x8 sheet. I figured I get it to the size of my rafts right away. They said it did not matter what size I wanted it was all the same.  I am getting it from a plant right in Colorado.

 

Should I ask if I can get a higher weight?  I noticed that in the post earlier I should not get anything lighter than 2 lbs.  I will ask them for 2 and 2-1/2 lbs to see the difference.

 

Also is anyone else interested in the colorado area in getting some?  Maybe we can get a discount if we can all get together on a purchase.

 

I am looking at  104 pieces and will get more if it means we get a better price combined.  You can call me at 303-719-1890 or post it here.

[David Hart]

Joe, Like Chris Smith mentioned....try calling White Cap (HD Supply)...see what they can get it for.

You said you were looking for 104 pices, do you mean 2' x 4' pices... 26 full sheets ?   I would think the factory would be charging more to cut it for you. (Unless their labor doesn't cost them anything ?)

The price you were given, seems (too) high. We just bought (from White Cap in FL) ....25 sheets (4' x 8') of 2 1/2 pd for less then what you were quoted for 1 1/2 pd....including our tax and delivery.   We probably could do better, if we bought straight from the manufacture ourselves. I wouldn't think it would cost 'that much more' in CO then in central FL.

Joe, I'm the one that made the comment about buying the denser EPS. My opinion... 'At least'  buy 2 pd....I myself, wouldn't buy anything  'less then'  2 1/2 pd. Try to check out some samples, before you buy

Good luck Joe.

 

[Joe Bifano]

Yes I need 26 full sheets or more.  They told me they get it in 6'x4x8 blocks and have to cut it to 4x8 anyway so 2x4 would not cost anything.

 

So are you getting your 2-1/2 lb 4x8 sheets for less than $34?  

 

I have to see if there is a white cap here in Denver.

[David Hart]

Maybe they aren't manufactureing it ...just buying and cutting it to size. That might explain the cost differances (?)

Yes, we paid less then $ 34, for a 4' x 8' sheet of 2 1/2 pd.

 

[Chris Smith]

Thanks for your input David! You have given us an alternative to blue foam.