Sunday, August 26, 2012

Types of Wood & Wood Specifications for Home Interiors

Over the course of the last few years the maximum number of queries I've received from my readers has been around the type of wood to be used and the what wood specification one should look for for different interior applications.

While part of the above query is answered in my earlier article on "What Material to use for Woodwork" I guess looking at the number of questions that have come in on the topic there is need for the article to be much more descriptive especially around the type of wood and their specifications. This post will try to do just that, also please read this in conjunction with the earlier post ("What Material to use for Woodwork")

Note: None of the Images below are my own - these have been downloaded either from Wikipedia or other open sources


1) TYPES OF WOOD FOR COMMON WOODWORK




PLYWOOD

A] PLYWOOD: 

Most people recognize this. These  are sheets of wood pasted together. However plywood comes in many specifications based on the chemical treatment of the wood and the glue used to bind the sheets together which determines its type of use - see the specifications section below.
Also - Plywood is available in multiple thickness from 2 mm to 38mm






BLOCK BOARD

B] BLOCK BOARD: 

This is cubical stocks of wood sandwitched between two thin sheets of Ply. As is obvious from its construction block board has higher  resistance against warping or bending. It is available in the standard thickness of 16, 19 & 25 mm
Again Blockboard comes in different specifications that determine its use in interior applications...more on that later







MDF

C] MEDIUM DENSITY FIBRE (MDF): 

MDF in engineered wood basically made from wood pulp. As is obvious from its construction MDF has low resistance to warping/ bending & moisture. Also nails do not hold well to join MDF sheets together, they need to be either screwed or joined using a minifix (google for it...). Because of this a lot of carpenters are not comfortable working with MDF. The good thing about MDF however is that you get "pre laminated" MDF in different colours, shades & textures and if used intelligently it can help bring down the cost of construction & also enhance the look of woodwork.

D] PARTICLE BOARD: 

This is chips of wood glued together and pressed into sheets. Particle board is the cheapest of the above 3 options, it however has least resistance to moisture. Because of its low density & weight Particle board offers good resistance to bending especially in applications requiring long panels (such as a 9 foot high wardrobe doors). Particle board also is available in "pre laminated" form and its correct use can help bring down construction cost.


2) WOOD STANDARDS AND SPECIFICATIONS:

Indian standards are not very well documented and there isn't much user understandable documentation available. What I have mentioned below is built on current market terminology & the products available in the market for a layman to make sense of the same. The paragraphs below are not meant to stand up to an ISI inspection but should definitely help "YOU" make informed decisions.


A) "Plywood" Standards and Specs: 


1. IS 303 Specification: This is the ISI or BIS Specification for Plywood. This is further divided into (1) MR Grade and (2) BWR Grade

  • MR Grade: Stands for Moisture Resistance - MR Grade Ply is basically regular plywood. This is also sometimes called Commercial Ply. In laymans terms this can be used everywhere except in the Bathroom & Kitchen.

  • BWR Grade Plywood: This is Boiling Water Resistant Plywood. Some companies call it BWP (Boiling Water Proof) Grade however the Bureau of Indian Standards has officially done away with the BWP terminology. In layman's terms this wood is also mentioned as Marine Ply & is for use in the Kitchen & Bathroom.
Note: Recommendation for Kitchens is therefore "IS303, BWR Grade Plywood" - The shopkeeper in the wood store will have little to fool around if you use the above phrase. Simple isn't it :)

2. IS 710: This is the "Formal" Standard for "Marine Grade" Plywood - used for making boats & ships...hence this is topic for a blog on shipbuilding & not here :)


B] Block Board Standards and Specs


The Bureau of Indian Standards has the IS 1659 Standard for Blockboards. Again this is subdivided into MR Grade (Commercial Board) & BWR/ BWP Grade (Boiling Water Proof)

Explanation on where to use blockboard and where to use Ply is on my other post at What Material to use for Woodwork



C] Standards for Particle Board and MDF: 



In India Particle board & MDF are at a stage of nascence where they are bought based on the Brand Name rather than on the ISI Standard. Some manufacturers do cite exterior Grade & Interior Grade MDF/ Particle Board, however personally I prefer to go with a good brand and the range of colours offered than the "Grade".

That does it for now I guess and as always would welcome any Bouquets & Brickbats

Signing off,

Nandita

PS: If you have a question to ask then please noteThe Q&A/ Comments interface on this blog below is unable to scale to the number of questions that we have been getting. Hence even if you post a question I will be unable to reply to it due to technology limitations. To do away with this issue we have launched the Q&A module on The Studio website

Hence if you have a question or if you posted a question earlier and did not get a response then please post it again at  https://thestudiobangalore.com/questions-and-answers/ so that I am able to see and answer it

Regards
Nandita