# OSB to build viv?



## Pepper Pot (Jul 12, 2008)

I am going to build a 4.5' viv out of this stuff as it is very cheap and also looks very natural inside ... but I am going to paint the outside white...

just a few questions...

do I need to coat it with anything? if so then what?

is OSB strong? do I need anything to support the roof in the middle?

and what do I use to attatch it together? do screws split it?


thanks


----------



## Jim2109 (Mar 30, 2009)

youll need to seal the inside with yacht varnish or something similar, especially if there will be high humidity inside.

strength wise it is pretty strong, stronger than chipboard, more rigid than MDF, but slightly weaker than plywood. you wont need to support it so long as you are using 15mm or thicker. if using 12mm then you may need to support it if there is a very large area that isnt supported by the sides (e.g. 4 ft x 4 ft or more)

to attach it together use primarily wood glue. the method i personally use (its the same method i use for MDF as well) is to use drywall screws! they have a much thinner shank which means they are less prone to splitting wood. they obviously arent as strong as normal wood screws, but they dont need to be. the way i do it is to pilot drill the holes 1-2mm smaller than the screw shank. i put a hole every 5-10cm. run glue along all joints, then screw it together to clamp it. once the glue dries the screws arent doing anything, the glue is as strong as the wood itself once fully dried. the screws are only there to locate and clamp the pieces whilst the glue dries.

this has worked for me in the past with great success, but youll struggle unless the wood is at least 15mm thick. any less and it tends to split too easily from the sides.


----------



## Pepper Pot (Jul 12, 2008)

Jim2109 said:


> youll need to seal the inside with yacht varnish or something similar, especially if there will be high humidity inside.
> 
> strength wise it is pretty strong, stronger than chipboard, more rigid than MDF, but slightly weaker than plywood. you wont need to support it so long as you are using 15mm or thicker. if using 12mm then you may need to support it if there is a very large area that isnt supported by the sides (e.g. 4 ft x 4 ft or more)
> 
> ...


thanks for your help! 

B&Q sell 9mm thick OSB in the perfect size that I need 

the 15mm and 18mm are far too small

they do sell an exterior OSB (dont know what the difference is) that is 11mm thick and is also the perfect size I need

the viv dimensions are; 54" x 18" x 18"

the sides will sit ontop of the bottom and under the top (not attatched on the outside of the top and bottom)

would I need something to support it?

thanks


EDIT: on the B&Q website there is 18mm thick OSB which is the same size as the 9mm I was going to get... but why is it £10 dearer? is it an error on the website?

because they have 11mm (which is bigger) that is only £1 dearer than the 9mm I was going to get....


http://www.diy.com/diy/jsp/bq/nav.jsp?isSearch=true&fh_search=osb&x=0&y=0


----------



## Pepper Pot (Jul 12, 2008)

please help me peeps :mrgreen:


----------



## Jim2109 (Mar 30, 2009)

you can get OSB in 2440mm x 1220mm (8ft x 4ft) sheet as well as the smaller sheets. chances are your local B&Q just doesnt have the larger sheets in stock. also the thicker sheets are always more expensive, 18mm is double the amount of wood compared to 9mm! see if they can order it in? alternatively wait until Tuesday and take a trip to your local Jewsons or builders merchants

given that your ends are only 18" x 18" you may get away with 9mm thick, there is no large unsupported area so it will probably hold up just fine. you will just have to either be very careful screwing into the ends of it, or dont use screws and simply glue and clamp. youll need good clamps though. sash clamps are the best way to do it, they typically arent particularly cheap. in fact they would more than offset the price difference between 9mm and 18mm sheet. if you pilot drill and use drywall screws i think you might just about get away with screwing into 9mm sheet though


----------



## Meko (Apr 29, 2007)

you can also get timber quite cheap from B&Q so you could build a frame inside it to strengthen it.


----------

