Friday, October 14, 2011

Frost heaving and cold bridge fixing in foundation wall

Last fall we got a new big sliding door to our garden deck. During the winter we had problems opening it, probably due to frost heaving. Our carpenter suggested we should insulate the outside of the concrete slab that the house is built upon. This concrete is also a nasty cold bridge into the house floor. So I got the spade out and started to dig.

The concrete slab is about 50 cm ( 2 feet) deep, at least around the perimeter. I also removed the lower plank to make sure to expose all of the concrete.

Today it is common to add 5 cm ( 2 in) of styrofoam insulation to the foundation wall, so I decided....

...5+5 cm should be good. I think it is a good idea to add as much insulation as possible while at it. I managed to cover all the exposed concrete.

Then there is an issue of leading any water away. So I added some fabric, "Leca balls" and a drainage pipe.

Close it up.

I also added 60cm of 5 cm thick styrofoam from the wall and out. This will also help to insulte, and will later be hidden under the new deck that will reach all the way to the sliding door. All set for the winter! When it gets real cold, it will be interesting to compare inside floor temerature close to this wall  to similar positions close to walls with no foundation wall insulation.
Update: It turned out that the problem with the sliding door was the upper wood above the sliding door that twisted during the winter. Some additional screws have now solved that problem.

Summary in Norwegian: Vi har installert en stor skyvedør mot hagen i vårt rekkehus fra 1978. Forige vinter begynte den å gå treigt, antagelig på grunn av telehiv. Dermed gikk jeg i gang med drenering og isolering av betongplaten som hele huset står på. Hensikten er å unngå at det blir frost under denne, og å fikse den enorme kuldebroen det er å ha sementgulvet i stua koblet rett ut i kuldegradene utenfor. Isolasjon er ikke noe man skal spare på, det er bare å kline til med det det er plass til. Her ble det 10cm mot veggen og  5cm plate 60 cm ut fra veggen. Til sommeren kommer vår nye hage platting her oppå isolasjonen i bildet. Andre steder i hagen planlegger jeg å få hvertfall de 10cm mot muren. Gleder meg til å se hvor varmt gulvet blir der hvor det er ekstra utvendig isolasjon i forhold til der hvor det ikke er. 

Sunday, May 15, 2011

One hidden master switch for TV, PS3 and surround sound

Kill your standby losses with a master switch.Below our TV we have a decoder, HDMI switch, PS3, Wii, and a sourround sound amplifier. First I tried to use a smart strip to turn off everything when the decoder goes into standby, but it was difficult to adjust the sensitivity, because the decoder used almost the same amount of current in standby as in normal use! So I simplified and made an easy to access master switch placed behind the TV screen (blue arrow). It turned out real good. The kids love it since it is much faster than using all the remote controlls. On an average day our family uses 1.2kWh on our entertainment centre. Our plasma screen uses about 170W on an average bright picture when set in standard display mode. When set to dynamic it uses almost twice as much. So keep the brightness down, and turn everything completly off when not in use.

Saturday, January 1, 2011

Insulate inside walls step by step

Our wodden house from 1978 has only 10cm (4") insulation. This winter I decided to add an additional 10 cm of insulation to the inside of the wall while upgrading our home movie theater in our living room. I wanted to hide all electrical and video/audio wires. I did some research on how to do this correctly, while keeping a tight vapor barrier. Here is how I did it, step by step. 

 This is a section of the original wall where there is also a window. I started by removing the winow trim and cutting away 10 cm of our wooden floor to give room for the new wall.

With all the dry wall removed you can see the old 0.15 mm thick plastic vapor barrier. It should be placed on the warm side of the wall. In Norway that is the inside of the wall. It is, however, ok to have a maximum of 1/4 of the wall insulation on the inside of the vapor barrier.

Since the original insulation was in the vertical direction, I added the next 5 cm in the horisontal direction. Then I added the new vapor barrier which was taped together with the old one. Any holes found was fixed with some duct tape. I also useed silicon around adjacent walls. It is very satisfaying to have a completely tight barrier.

Here is where you see the advantage of having the inner most 5cm of insualtion inside of the vapor barrier. All electrical wires, can be hidden here without any worries of punctuate the barrier and getting condensing problems in the wall. The inner most 5 cm insulation was in the vertical direction.

Insulation on the inside completed, a full 20 cm in total for the wall. Some of the dry wall in place. To the very left you can see a hole for a speaker cable.

There it is. The completed wall with the first layer of paint.
You can find more technical details on vapor barriers here: Vapor Barrier explained