roof insulation required on tenant upfit R-38?

[syarn]

2009 IECC

2200sf type IIB assembly A-2

alteration of existing tenant space at covered mall building in austin texas to salad restaurant;

does R-38 batt have to be installed below the deck minimum if insulation is added per table 502.2 (1)?

the existing roof deck is R-6.24 and the engineer & architect directed to provide R-13 batt below deck to meet the design basis of the HVAC.

is there an exemption for alterations?

 

[Keystone]

Insulation entirely above deck = R20ci

Metal bldgs (with R-5 thermal blocks) = R13 + R13

Attic and other = R38

If an engineer and architect are involved why would they not take the time to perform a ComCheck?

 

[syarn]

we are working to get the comcheck now....thx.

I do see where instead of the prescriptive method u can use trade-off, system performance or whole bldg energy analysis...

 

[Keystone]

Yes you can convert over to U Factor

502.1.2 U-factor alternative. An assembly with a U-factor, C-factor, or F-factor equal or less than that specified in Table 502.1.2 shall be permitted as an alternative to the R-value in Table 502.2(1). Commercial buildings or portions of commercial buildings enclosing Group R occupancies shall use the U-factor, C-factor, or F-factor from the "Group R" column of Table 502.1.2. Commercial buildings or portions of commercial buildings enclosing occupancies other than Group R shall use the U-factor, C-factor or F-factor from the "All other" column of Table 502.1.2.

 

[steveray]

I don't think we require it if the envelope is already in place and there is not a great deal of work going on.....on second reading, I guess if you are adding anything (R13), it should comply...

 

[Frank]

You need to look at the locally adopted Chapter 1 scoping provisions.

See 101.4.3 of the 2009 IECC for unmodified scoping--highly unlikely to have been kept intact in adotion process.

 

[steveray]

Frank has it right with 101.4.3.......if it is a change of use that is another matter 101.4.4....