Local Professionals – World Class Standards

Successful Solid Timber

Floor Installation

Three steps to success

1. Know the characteristics of the product

2. Know the environment you are laying in

3. Laying taking these aspects into consideration

Step 1

1. Know the characteristics of the product

- Floor colour

- Floor grade

- Moisture content

- Shrinkage and swelling characteristics

- Effect of board density

Colour is determined by species

The species or species mix determines the blend of colour tones in the floor

Spotted Gum Blackbutt Grey Ironbark

Grade determined by features

The grade determines the character of the floor

AS 2796 Select Grade Medium Feature – Standard Grade High Feature Grade Lightly featured Moderately featured Highly featured

It can be acceptable that not all boards in a finished floor may meet the grade. Some species have more features than others and therefore some Select Grade floors have more features than others.

Resistance moisture meters are the most useful for installers

Checking board moisture content

They provide a reasonable estimate Readings need to be corrected for temperature and species Moisture contents and cover widths require checking and recording From this you can assess the manufacture and likely future movement

Then don’t lay floors But I don’t

use a meter

Understanding Shrinkage and Swelling

This is the most important concept with timber flooring Flooring moisture content affects expansion and shrinkage

In high humidity, boards expand In low humidity, boards shrink

Hygrometers measure humidity

Relationship between Equilibrium Moisture Content, Temperature and

Relative Humidity

8.08.59.09.5

10.010.511.011.512.012.513.013.514.014.515.015.516.016.517.0

50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80

Relative Humidity (%)Eq

uilib

rium

Moi

stur

e Co

nten

t (%

) 15°C 20°C 25°C

Timber in a room at 20°C

and the relative humidity is 60%

then the timber will in time try to attain 11% moisture content

Movement and Moisture Content

Board expansion

An 80 mm wide hardwood board will try to expand by about 0.25mm across its width for each 1% increase in moisture content.

In floors this movement is restrained to a degree by the fixing but adequate expansion must still be provided.

Allow for natural floor expansion

Minor gapping does not detract from a floors appearance and is also acceptable.

Heating and floor to ceiling glass promote some gapping.

Shrinkage gaps are a natural part of timber floors

Board shrinkage

The higher the density the stronger the boards. This is more important than you may think!

Board density and strength

Under expansion lower density boards crush and can gap.

High density boards can be more powerful than their fixings.

Step 2

2. Know the environment you are laying in

- Regional influences

- Locality influences

- The internal environment

- Assessing the subfloor spaces

- Assessing concrete subfloors

Know the installation environment

• Tropical climates – floors generally expand after installation

• Temperate climates are more closely aligned to the manufactured moisture content

•Dry climates – floors generally shrink after installation

Relative Humidity Tropical, Temperate and Dry Climates

20

30

40

50

60

70

80

90

100

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecMonth

Rela

tive

Hum

idity

(%)

Innisfail - Ave Ext EMC 16%Brisbane - Ave Ext EMC 12%Mt Isa - Ave Ext EMC 8%

Flooring manufactured to an average MC of

11% won’t change MC at 65% RH.

Regional influences

Acclimatisation can reduce movement effects

Know the installation environment

In the mountains, there is more rain, mist, lower temperature and higher humidity. Floors at 11% to 16%

City suburbs. Lots of roads and closely spaced houses. Water drains away quickly. Floors at 10% to 11%.

West of the mountains. Periods of very dry winds as well as rainy periods Floors at 9% to 12%

On the foreshore. Cool sea breezes. Floors often at 12 to13%.

Locality influences Gold Coast to Beaudesert

Influences on the internal environment

Solar gain from floor to ceiling glass

Mountains - variable

Green farmland - Moist

Gully - Moist Dry low rainfall climates

House environments requiring greater consideration

Heating/ cooling

Assessing subfloor spaces

700 mm spacing

Vent spacing

For floors with natural ground beneath

Must be dry!

Must be ventilated!

For floors with natural ground beneath

Assessing subfloor spaces

Assessing concrete subfloors

For floors over concrete slabs

They need to be FLAT - Grinding and levelling may be necessary.

They need to be DRY - Old slabs are not necessarily dry slabs. Vapour barriers need to be considered. When adhesive fixing they need to be CLEAN and STRONG – Otherwise delamination results.

Step 3

3. Laying taking these aspects into consideration

- What you should now know prior to laying

- Preparing the subfloor

- Considering acclimatisation

- Providing for floor expansion

- Use recognised fixing practices

What you should now know!

• Species and grade considerations • Density and strength considerations • Estimated moisture content and board

widths • Expected effects from the external and

internal environment • Subfloor suitability and prep requirements • Consideration on acclimatisation and

expansion allowance

Before fixing the flooring

Considering acclimatisation

Acclimatising is simply getting the moisture content of your flooring closer to its expected in-service moisture content.

Therefore shrinkage or swelling will be less after installation.

Installation and in-service environments can differ greatly!!!

At start

Two weeks later

Considering acclimatisation

Regular gaps

Cork

Expansion allowance is a must not an option

Providing expansion allowance

The more adhesive that is used the less effective that joints are and the greater the pressure there is in the floor that can contribute to peaking.

Use recognised fixing practices

Lay to industry recommendations or manufacturer instructions

Don’t think that you know better!

Keeping records

One last thing. Record everything about the job. You just don’t know when you are going to need it. Moisture tests, checks on the subfloor, batch numbers, site conditions. They are all important! Write them down.

Your Wood Solutions Guide

Step 1 Step 2 Step 3 Step 3

The coming update

• New title – Solid Timber Flooring – Industry standards

• New section on Parquetry & Pre-finished solid • Updates with the latest

information from ATFA info sheets

Thank you