b'ada (NRC) in collaboration withSIGDERS has been a key actor theSpecialInterestGrouponin this research for two reasons. Dynamic Evaluation of RoofingFirst, they provided the requiredField monitoring is a challenging research domain, Systems (SIGDERS) consortiumnetwork to identify the suitable to conduct a wind load investiga- buildingforfieldmonitoring, tion to verify the suitability of theand they helped get the buildingparticularly if the objective is to compare results current wind load provisions forowners approval to install pres-low-sloperoofs.Theinvestiga- sure sensors on the roof. Second, tionaimedtobenchmarkwindas a final user of code provi- with code provisions.load specifications with the windsions, their advice regarding the loadmeasuredfromanin-situpracticalityofprovisionsand building and wind tunnel simu- designrequirementshasbeen lations. The synergy of full-scaleessential to integrate science and measurements with wind tunnelreal-world conditions.simulationsisrecognizedtobeBased on the previously not-a powerful approach to validateed selection criteria, the research codeprovisions.Thefull-scaleteam selected the building shown dataprovidetherealphysicsin Fig. 1a and Fig. 1b to verify the (rightscaleandrightdynamiccodeprovisionsforlow-slope interactions),whereasthewindroof buildings [Fig. 4.1.7.6.C in tunnel simulations provide con- NBCC]. The buildinghereaf-figurationsnotpossibletoob- ter referred to as the IOWA build-tainfromfieldmeasurements.ingis a manufacturing plant in ThistridimensionalapproachSigourney, Iowa. It is situated in offieldversuswindtunnelver- open terrain with a neighbour-sus code provides a valuable per- ing construction located to the spectivetoverifythesuitabilitynorth. It has a square shape plan ofcodeprovisions.Thisarticlemeasuring 240240 ft. (7373 presents the work done by NRC- m), a ridge height of 23 ft. (7 m) SIGDERS to verify the suitabilityand a roof slope of 1.4 degrees ofthecurrentwindprovisions(2.5 per cent) with no parapets. for low-slope roofs in NBCC. ItAdditional details of the IOWA isanticipatedthatthisresearchbuildingandroofcomponents will contribute to the discussioncan be found in Chavez et al. 7ofwhetherthecurrentNBCCTwoareasontheroofwere code provisions need to be revisedinstrumented (northwest corner or not. 3030 ft. [99 m] and south-Field Monitoring: IOWAwest corner 6060 ft. [1818 m]) as shown in Fig. 1b, with a Building totalof21pressuretaps.The Field monitoring is a challeng- tapswerestrategicallydistrib-ing research domain, particularlyutedtocapturewindloadson if the objective is to compare re- thethreeroofzones(Corner, sults with code provisions. The in- EdgeandInterior)definedby duced variability of the approach- NBCC. The core of wind load ing flow due to the building itselfmonitoring is the pressure sensor orupwindsurroundingsmakesapproachdevelopedbyNRC. it very difficult to generalize theFig. 2 shows some details of the roof wind load. To minimize thesensor. The device is built using a uncertaintiesandmaximizethe12-in.-long (300-mm) and -in.-validityofcomparisonsoffielddiameter (6.4-mm) copper tube, data and code provisions, the se- which is bent at the external end lection of the building is a criticaltopreventrainwaterintrusion. component of this research. TheThe external end is located close selectionprocessincludesthreetothemembranetocaptureViana Roong & Sheetmetal Ltd. is a progressive roong, main criteria: the static pressure acting on thewaterproong and restoration company who has successfullyGeometry:Theselectedmembrane. The internal end is completed thousands ofprojects over the past37 years. buildingmustbeanidealconnected to a flexible tube (10Our services include all types of roong, sheetmetal and siding,representation of the build- to 12 in. [250 to 300 mm] long) ing specified in the code. that is connected to the pressurecaulking work, waterproong and more.WindExposure:Theloca- transducer box, where the wind tion should be in open ter- pressureisconvertedintoan rain to avoid or minimize theelectrical signal. A reference pres-effect of adjacent buildings. sure is required to quantify theAccessibility to the roof deckdifferential pressure, and a data(toallowtheinstrumenta- acquisition system is necessary to tion installation). store and process the data.To overcome these challenges,Thefielddataarecollected NRCrequestedthecollabora- continuouslyatarateof100 tionofSIGDERS.SIGDERSsamples per second, which gen-is a North American non-profiterates a massive amount of data.74 Advance Road, Toronto|416.763.2664|vianaroong.comorganizationcomposedofroof- A post-processor was developed ing manufacturers and provincialto extract sections (segments) of roofingcontractorassociations.relevant data that respond to a ORN THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ONTARIO ROOFING NEWSISSUE 4 2022/2315'