Many homes around Toronto have attic spaces are not ventilated or insulated properly. This can result in a roof not lasting as long as it should, high heating and cooling costs, mold, and ice damming.
We would like to give an overview of how we have overcome some of these issues for our clients.
First off, if your home has wood soffits then sections of the wood soffit should be cut out to increase airflow. For this client we are cutting out all the plywood soffit to maximize airflow into the attic. Keep in mind that this layer of plywood can be hidden under a layer of existing soffits.
With the installation of new aluminum soffits the plywood can be completely removed with out jeopardizing the integrity of the roof. The plywood was used many years ago to seal up this area but today aluminum soffits will take its place and vent much more effectively. New homes today do not have a layer of plywood, just aluminum or vinyl soffits.
Cutting out all the plywood is more labour intensive than just cutting an extra ventilation holes every so often. It does however let the attic breathe much better. Also removing the plywood at this home allows us to see some pot light wires that were chewed bare by squirrels. This resulted in a service call from our licensed electrician to correct the hazards.
It takes about a 1/2 to full day to cut out all the plywood on a typical Toronto home. The clean up is intensive as usually there is much debris sitting on top the old plywood. This is where hiring a thorough soffit, fascia and eavestrough company pays off because they are knowledgeable and care about the aesthetics and very importantly, the function of your new system.
Now that the plywood is out we look up into the cavity to see how many rafter vents have been installed if any. They are a simple foam chute that is stapled to the underside of the roof deck. They are needed to prevent any insulation in the attic from coming out onto the soffits and also to allow an air gap between the roof deck and the top of the wall plate (in other words this gap into the attic is narrow and can get plugged by insulation easily and that’s not good for airflow).
We like to put them between every rafter to promote even airflow. With the wood soffits removed we can often slide the first rafter chute in from the outside. Then its gets stapled to the plywood and a piece of batt insulation is fitted under the chute to prevent the new attic insulation from flowing out onto the yet to be installed vented soffits. Many insulation companies might say this is overkill on the baffles so check with them for how many they will install.
Let’s now take a look inside the attic. Lights need to be set up as there is very little light in the attic.
We have continued these rafter chutes about 6 feet up the roofline because this roof is about a 5/12 pitch (average steepness and can easily be walked on). Extending the chutes up this far allows for a deep layer of blown in insulation to be applied without covering the top end of the chute with insulation and blocking airflow. Its tight/hard work to reach out to this narrow area of the attic space. Care must be taken as not to put pressure on the ceiling below or a person or portion of, may end up in your living room!
Once all these are stapled securely in place around the entire perimeter of the attic we are ready to start the blown in insulation process.
This home has a thin layer of batt insulation from when the house was built in the 1950’s. It’s important to clean up any debris to make an even, flat surface so an even layer of insulation can be blown in. The debris can be bagged and taken out to be disposed of.
The most thorough way to take care of this old insulation is to have it completely sucked out with a large vacuum hose. This will totally get rid of all the old product and then you have a nice clean ceiling. This can now allow for you to blow the attic in with loose fill or first seal the ceiling with a spray foam to give a super tight seal which can act as a vapour barrier and stop all drafts down to the living area. Once a layer of spray foam is installed many companies will then blow a layer of loose fill over top to keep the cost down.
The ventilation code has not changed since the 1950s as we can see by the information on the piece of old insulation in the attic.
The other very important part is that all the new soffits be ventilated. Every piece will have small little slits in it to allow air to pass through the aluminum panel and up into the attic. Now you can be confident you have done major improvement in the attic temperature which will slowly begin to pay you back with each passing year. A longer lasting roof, no condensation or mold problems, an air conditioner that runs less frequently, and less chance of water penetrating your roof/ceiling due to ice damming in the winter.