11:04AM | 05/17/04
Member Since: 05/16/04
2 lifetime posts
Hello All:

I need to insulated the roof of my 104 year old house in QC. The rafters are 2x6, 24 on center.

How do I do this best?

I know I need at least 1" for ventilation, that leaves me with 5" for insulation. Is it possible and smart to use rigid insulation between the rafters? Should I add to the rafters with framing from the inside?

How does one get an R-value of at least 30 when one only has 6" rafters?

Thank you for all tips or hints.



12:32PM | 05/17/04
Member Since: 04/03/04
30 lifetime posts
Find a wholsaler of EPS foam near you and you can have it cut to whatever dimensions you'd like. If you use 2# EPS, 6" will give an R value of 30.


03:17AM | 05/18/04
Member Since: 05/16/04
2 lifetime posts
Thank you for the response. Of course, I have a follow-up questions:

From what I just looked up on the internet, EPS foam can have a maximum R-value of 4 point something. So if I leave 1" for ventilation (Is that enough?), 5" of insulation will give me a R-value of a little over 22. Am I looking at the wrong material? Do I not need to ventilate my roof?Can you be more detailed? And how do I attach the panels in the bays. Toe nail each?

How about the variations in rafter spacing? Fill the holes with spray-in foam?

Thank you.



05:19AM | 05/18/04
Member Since: 04/03/04
30 lifetime posts
That's one of the nice features of EPS. You can measure all of the spaces that you need to fill between the rafters, and have the EPS cut to fit perfectly. You can put it up with construction adhesive and a calk gun. You can use the minimal expanding foam in a can to fill any small voids or seams as well. The "R" values change depending on the density of the foam you use, ie: 1#, 2# etc. Regarding ventalation, check with a local roofer in your area as per your climate etc. Here's a link for EPS suppliers in the USA.


Post a reply as Anonymous

Photo must be in JPG, GIF or PNG format and less than 5MB.


type the code from the image


Post_new_button or Login_button

Few projects are more fun than upcycling a vintage piece in a surprising way. Outfitted with a sink and a delicately tiled... Built on a rocky island in the Drina River, near the town of Bajina Basta, Serbia, this wooden house was cobbled together ... Large steel-framed windows flood the interior of this remodeled Michigan barn with daylight. The owners hired Northworks A... Edging formed with upside-down wine bottles is a refreshing change. Cleverly and artistically involving recycled materials... A Washington State couple called on BC&J Architects to transform their 400-square-foot boathouse into a hub for family bea... Similar to the elevated utensil concept, hanging your pots and pans from a ceiling-mounted rack keeps them nearby and easy... For windows, doors, and mirrors that could use a little definition, the Naples Etched Glass Border adds a decorative flora... The thyme growing between these stepping stones adds a heady fragrance to strolls along this lush, low-maintenance garden ... Decoupage is an easy way to add any paper design to your switch plate, whether it is wallpaper, scrapbook paper, book page... Twine lanterns add pops of crafty—but sophisticated—flair to any outdoor setting. Wrap glue-soaked twine around a balloon ... When securely fastened to a tree or the ceiling of a porch, a pallet and some cushioning make the ideal place to lounge. V... Reluctant to throw away any of those unidentified keys in your junk drawer? Hang them from a few chains attached to a simp... A stripped-down model, sans screened porch, starts out at $79,000. Add the porch, a heated floor for the bath, and all the... Salvaged boards in varying widths and colors make up the dramatic accent wall in this attic space. The high-gloss white of... This garden shed has been decked out to the nines. Designer Orla Kiely created the intimate home for a flower trade show, ...
Newsletter_icon Google_plus Facebook Twitter Pinterest Youtube Rss_icon