Timber-hirsi Oy

When good thermal insulation is needed, double log is right choice for wall material. In this kind of construction there is a space between two logs, which can be filled with wood fibre insulation. When k-value for 202 mm thick log wall is 0,53 it is improved to 0,23 with insulated double log wall. (k-value is used to descripe capacity of thermal insulation).

Even an air filled space without any insulation gives better thermal insulation capacity to wall, than could be reached with solid log construcion. In Central Europe this building technic is popular.

	Log	+ Insulation	+ Log	= Thickness	u-value
	70				1,28
	90				1,05
	94				1,02
	114/138D				0,87
	202				0,53
	Log	+ Insulation	+ Panel	= Thickness	u-value
	70	50	20	140	0,46
	70	100	20	190	0,30
	90/94	125	20	235/239	0,24
	114/138D	125	20	259/283	0,23
	Log	+ Insulation	+ Log	= Thickness	u-value
	70	100	70	240	0,26
	70	120	70	260	0,23
	90/94	100	90/94	280/288	0,24
	90/94	120	90/94	300/308	0,21
	90/94	140	90/94	320/328	0,19
	114/138D	100	114	328/352	0,22
	114/138D	140	114	368/392	0,18
sources: EGH Entwicklungsgemeinschaft Holzbau in der Deutschen Gesellschaft für Holzforschung, VTT Rakennus- ja yhdyskuntatekniikka, testausselostus Nro RTE2195/01; Hirsiseinäelementtien lämmönläpäisykertoimien määritykset