This presentation. Roofs. Roofing. Roofs

Transcription

1 This presentation John Straube, Ph.D., P.Eng Roofing Low-slope Pitched Membrane, metal, etc. Roofs presented by Roofs 2 Roofs Roofs are significant proportion of the area of low-rise buildings Significant to total cost Major area for heat loss / gain Low-slope membranes usually need replacement every yrs. Wide range of membrane choices Insulation on top or bottom of membrane Green roofs = organic ballast.com Enclosures No. 3 / Joseph Lstiburek Roofs 4 Straube buildingscience.com 1 of 16

2 Protected Membrane Roof Joseph Lstiburek Roofs 5 Enclosures No. 6 / Inverted Roof Pros: Preferred approach Exterior insulation eliminates thermal bridges Protects membrane Cons: Added weight of ballast Can only use XPS Roofs 7 Enclosures No. 8 / Straube buildingscience.com 2 of 16

3 Exposed membranes Pros: Lightest weight Wide variety of insulation and membranes Cons: Exposed membrane! Enclosures No. 9 / Roofs 10 Special Applications Swimming pools Esp in cold climates Freezer buildings Esp in hot humid climates Air sealing details May need plastic pipe section to reduce thermal bridge MUST have a deck level air barrier Sealed at all edges, penetrations! Roofs 11 Roofs 12 Straube buildingscience.com 3 of 16

4 Sloped roofs Basic Physics are the same Slopes allows non-waterproof materials to be lapped shingle fashion Air leaky roofs require more ventilation Roofs 13 Joseph Lstiburek Roofs 14 Roofs 15 Roofs 16 Straube buildingscience.com 4 of 16

5 17 Joseph Lstiburek Roofs 18 Joseph Lstiburek Roofs 19 Roofs 20 Straube buildingscience.com 5 of 16

6 Roofs 21.com Roofs 22 Joseph Lstiburek Roofs 23 Roofs 24 Straube buildingscience.com 6 of 16

7 Joseph Lstiburek Roofs 25.com Roofs 26 It s a roof, not a pool Roofs 27 Roofs 28 Straube buildingscience.com 7 of 16

8 It s a roof, not a ice rink Money spent on roof slope is one of the best bargains in the construction business Wayne Tobiasson, CRRL Roofs 29 Roofs 30 This is not a solution Slope 2% is a good design value for membrane Account for roof sags: long span steel often sags more than slope Roof drains at columns Metal panel slopes Higher ribs, allow lower slopes Beware laps Roofs 31 Roofs 32 Straube buildingscience.com 8 of 16

9 Transitions / Penetrations Roofs 33 Roofs 34 Parapets Rain leaks at parapet Air leaks everywhere Heat leaks everywhere Roofs 35.com Roofs 36 Straube buildingscience.com 9 of 16

10 .com Roofs 37 Roofs 38.com Roofs 39.com Roofs 40 Straube buildingscience.com 10 of 16

11 Wall Transitions Roof to wall is one of the most problematic roof details Joseph Lstiburek Roofs 41 Roofs 42 Saddles Roofs 43 Roofs 44 Straube buildingscience.com 11 of 16

12 Roofs 45 Roofs 46 Reverse Laps Roofs 47 Joseph Lstiburek Roofs 48 Straube buildingscience.com 12 of 16

13 Flashing must go THROUGH a brick veneer to drainage plane Retention bar and reglet for solid masonry (if it is solid).com Roofs 49 Roofs 50 Roofs 51 Roofs 52 Straube buildingscience.com 13 of 16

14 Roofs 53 Roofs 54 Combine multiple penetration at doghouses Avoiding penetrations is always best Roofs 55 Roofs 56 Straube buildingscience.com 14 of 16

15 Ice Dams Roofs 58 Low slope metal Roofs 59.com Roofs 60 Straube buildingscience.com 15 of 16

16 Heat loss at Z-girts -Thermally break Z-girts -Steep slope to get water off the roof ASAP Roofs 61 Roofs 62 White roofs: the coming storm White roofs Lower heat gain Reduces drying out of roof Require better moisture control! Air barrier Construction moisture What air barrier Roofs 63.com Roofs 64 Straube buildingscience.com 16 of 16