NZBC H1: Solid Masonry Wall Insulation

By Bhavna Prentice

5 Comments

Published July 7, 2010

Bhavna is the Technical Marketing Specialist at Tasman Insulation, the manufacturer of Pink Batts insulation products. She holds a degree in Mechanical Engineering and is an experienced design engineer. Read all posts by Bhavna or subscribe by email.

One of the main changes in NZBC H1 is how solid masonry walls are now treated.

Download the current Pink Batts Thermal and Acoustic Insulation Product Guide

Before the change, if you were to design a home with a block or precast wall, the level of insulation needed to meet compliance was relatively low. Our Pink^® Batts^® masonry wall products were designed for this particular application.

But since the recent change in NZBC H1, if strapped and lined on the inside, solid masonry walls require almost the same level of insulation as a timber framed houses.

This now means the strapping must be 90mm to allow for the level of insulation generally required.

You may ask why this has changed, doesn’t the increased thermal mass of solid masonry walls allow for lower levels of insulation to be used? This is true, but when you insulate on the internal side, you are basically insulating the effect of the thermal mass out.

So what level of insulation should you be using?

In the case of a 150-200 series block wall Pink Batts Classic R2.2 Wall will meet the requirements under the Schedule Method.

For more information on the Pink Batts wall products available download our current Pink Batts Thermal and Acoustic Insulation product guide.

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5 Responses

Natasha
July 7, 2010 at 2:07 pm

We’ve found using Kingspan it reduces the thickness in strapping as its a very high density premium product that has a high R value.

[Reply]
Lee Wilkinson
July 7, 2010 at 4:21 pm

Are there any compliant 45mm products?

[Reply]
Natasha
July 7, 2010 at 4:39 pm

We had the salesman from Kingspan come visit us. You’rre best to contact them.
He brought a product that was 40mm thick and could have Gib stuck to one side as part of the fabrication of the product. Had a rating of 2.2 if I can recall rightly.
Saves strapping and lining as its all in one!

[Reply]
Aaron
July 13, 2010 at 10:55 am

Hi Bhavna,

Would you recommend installing building paper between concrete masonry block wall (plaster exterior finish) and pink batts wall insulation. Wall system is 190mm block / 90mm strapping (on DPC) – R2.4 wall batts.

Do you think extra protection in the form of building paper would be recommended between the masonry and the insulation?

Thanks

[Reply]
bhavna prentice:
July 13th, 2010 at 12:04 pm
Hi Aaron,

Yes, we do recommend installing a building paper between masonry walls and insulation as a safe guard.

[Reply]