how to tell if harboard is tempered

[Ravenswood Chicago]

I just purchase some tempered hardboard from my local home-improvement center.

I'm questioning whether this hardboard truly is "tempered".  How can I tell?  I'm skeptical because the hardboard has a light color instead of the traditional dark brown.  It's 1/4" and smooth on both sides.

I plan on using this a ceiling on a covered porch.  I want to use tempered as I understand it is better for exterior use than non tempered.

Thanks.

[blackhat]

Hardboard of any persuasion would be low on my list of choices for that application.

[Lynden]

The information below is from Wood Magazine. Tempered hardboard is darker in color because oil is applied to the surface followed by heat and pressure. The lighter-colored hardboards are either Service grade or Standard grade. Does your hardboard have a colored stripe(s) on the edge? There is a Composite Panel Association (link below) if you want more information.

HARDBOARD
Description: Ground wood pulp combined with resins and pressed into sheets. May be smooth on one or both faces.
Uses: Excellent for shop fixtures and jigs (especially the variety with two smooth faces) and benchtops. Use perforated hardboard for hanging tools.
Available Sizes: Available in two thicknesses: 1/8" and 1/4" in 4x8' sheets.
Common Grades: Service (2 green stripes), Standard (1 green stripe), Service-tempered (2 red stripes), Tempered (1 red stripe), S1S (smooth one side), S2S (smooth two sides)
Pros: Readily available, easy to cut, relatively stable, available with two smooth sides or one, takes paint well.
Cons: Standard and Service grades are susceptible to moisture, can't sand faces, flexible, edges easily damaged, holds fasteners poorly.
Where to find it: Home centers carry 4x8' sheets plus half and quarter sheets in standard and tempered grades. Look for the edge stripes.

http://www.compositepanel.org/userfiles/filemanager/72/

[Ravenswood Chicago]

That's great info.   I checked mine and it has THREE red stripes.  I'm having no luck looking on internet to see what 3 red stripes mean.

[Cooler]

Lowes and Home Depot both sell a resin bead board in both board and sheet sizes.  It is both waterproof and insect proof.  It comes in white so if that is your color, you put it up and forget it.  Use both stainless steel staples and construction adhesive.

http://www.homedepot.com/p/House-of-Fara...lsrc=aw.ds

https://www.google.com/search?q=resin+be...iling+&*

[ez-duzit]

Un-tempered is dull, rather soft and easy to break with your hand. Most of what you'll find at HD will be tempered. I would use stainless sheet metal screws to secure it.

[Robert Adams]

Tempered is smooth both sides as its pressed. Untempered is smooth one side and rough (like small waffle texture)on the back as its produced on a screen and not pressed between two rollers or flat plates.

[Ravenswood Chicago]

Lots of confusing info.  I've read that tempered is dark because of the oil used.  There are also different types of temper (Standard and Service).

I've never heard that Tempered has to be smooth on both sides.

Right now I have Dark Hardboard with a waffle back.  I also have light-colored hardboard that is smooth on both sides.

[Robert Adams]

The color has to do with the sawdust and glue used. The stuff that's smooth on both sides Is the best. I can only get that from a plywood supplier these days. The borgs don't carry it anymore.

[Lynden]

You can try calling DPI in Toledo, OH, to find out who sells their tempered hardboard in your area. They sell DPI tempered hardboard here in California. While you have them on the phone, ask them about the three red stripes.

http://www.decpanels.com/distributor/hardboard-specs

http://pacificpanel.com/page/product/name/hardboard/

http://pacificpanel.com/_images/9/169/pd..._sheet.pdf