Nascr s precise manufacturing tlerances deliver a prduct that resists shrinking, warping and twisting the mst cmmn causes f squeaks in flr systems built with dimensinal lumber. Ensuring a squeak-free flr, hwever, als requires attentin t detail during installatin t avid squeaks resulting frm cntact between metal n metal, such as nails n a jist hanger wd n metal, such as a jist s bttm flange n a steel beam wd n wd, such as a sheathing jint This guide has been prepared t identify installatin situatins that can result in squeaks, and t prvide infrmatin n hw t avid the situatins, r fix them if they have already ccurred. Hanger issues When jists are te-nailed nt a beam fr temprary supprt, and then hangers are installed, the head f the te-nail rubs against the side flanges f the hanger, resulting in a squeak. Squeaks can als be caused by a hanger rubbing against a defrmatin in the fundatin. Install the hangers n the beam prir t installatin f the jists, r ensure that te-nails d nt cntact the hanger flanges by mving the nails, r cmpletely embedding them in the wd fiber. Bearing issues Pry the hanger flanges away frm the nail head, and insert a shim r cnstructin adhesive t avid metal-n-metal cntact. When jists are framed directly nt the flange f a drpped steel beam and there is a gap between the bttm f the jist and the steel beam, the jists can shift dwnward when lad is applied, resulting in a squeak. Install strapping t the underside f the jists t ensure that the jists rest firmly against the supprts, r use a nailer plate. Install shims r strapping t ensure the jists rest firmly n the supprt. www.nascr.ca 1
Bearing issues (cnt d.) When the sill plate is nt installed in the right place it prevents the tp flange f the hanger frm being fully supprted. When a lad is applied, the tp flange f the hanger can rub against the face f the cncrete r beam, causing a squeak. Make sure the sill plate is installed flush with the inside f the fundatin r beam. Jack up the jist near the hanger t eliminate the gap. Use a stud wall, pst r ledger t supprt frm belw. When jists are imprperly set in hangers, it may create a vid between the bttm f the jist and the seat f the hanger. A squeak may result if the vid allws mvement when a lad is applied. Place the jist carefully t enable full bearing in the hanger. Squeaks can be reduced by placing a small amunt f sub flr adhesive in the hanger befre the jist is installed. If a hle is prvided, install a wd screw (#8 x 1½" max.) thrugh the bttm seat (install the screws befre the adhesive sets t ensure unifrm bearing). These steps are in additin t vs. a replacement fr the required jist fasteners. If a vid exists and yu can access the hanger, put a shim between the jist and the hanger. Fr jists with a directly attached ceiling, find the middle f the hanger, and make a hle thrugh the ceiling. Drill a hle larger than the screw shank thrugh the hanger seat and apply adhesive thrugh the hle. Draw the jist int the hanger with a single #8 x1¼" screw. Alternatively, yu culd install a wd screw at a 45 degree angle frm abve - drill a pilt hle larger than the screw shank thrugh the flr sheathing, the tp flange f the jist and partially int the beam. Put the screw thrugh the hle and draw the jist dwn int hanger. *Gap www.nascr.ca 2
Fastener issues When nailing is dne imprperly r inadequate nail diameters are used, it impacts the lad-carrying ability f the hanger and can als cause a squeak due t mvement between the jist and hanger. Fill every nail hle with the nails specified by the hanger manufacturer and ensure that the head f the nail is driven tight t the hanger. Cmmn jist hangers typically require a 3 lng 10d nail, which has a shank diameter f 0.148. Access the hanger and crrect the nailing. When sheathing nails barely hit the jist they d nt hld the panel tight. This enables the nails t rub against the side f the jist, and a squeak t result when the sheathing deflects. Exercise care when nailing sheathing. If pssible, remve the nails frm abve and reattach the sheathing t the jist. If the flr finishing is already installed, try t access it frm belw and bend the nail away frm the jist flange. Re-attach the sheathing t the jist frm belw. Mechanical & electrical issues When pipes, ducts r similar items are threaded thrugh Nascr jists, they may rub against the jist web and cause a squeak. Allw a ¼" clearance when cutting hles in the jist web. See the charts in the Nascr Installatin Guide fr allwable hle sizes and lcatins. Put plastic sleeves arund the threaded items. When items are hanging frm Nascr jists, they may rub against the jist flange and cause a squeak. D nt hang strapping directly ver the flanges. Cnnect strapping t a filler blck that is secured t the Nascr jist web, r install a shim between the strap and the jist flange. www.nascr.ca 3
Mechanical & electrical issues (cnt d.) When crss-bridging r blcking rubs n the jists it can result in a squeak. Ensure that crss-bridging, blcking and all ther elements are prperly fastened as per the Building Cde, r per Nascr s installatin guidelines. If mid-span blcking is required, ensure it is cut t fit tight and apply adhesive t the surfaces. Nail thrugh the sheathing int the blcking with at least tw 10d (3") bx nails and attach t bttm flange with 10d bx nails. Crss Bridging Sheathing issues Add required fasteners t prperly secure elements. Using screws rather than nails may be necessary due t access restrictins. When flr sheathing gets very wet during cnstructin it ften swells and shrinks after drying, leaving a vid under the nail head. When stepped n, the sheathing can mve and result in a squeak. Keep building materials as dry as pssible. Use prper adhesive and prper technique t bnd sheathing t the jists. There are a few ways t re-attach the flr sheathing if this ccurs: Pull back the carpet, drive the nails flush and install a wd screw near the nail. Install scred screws thrugh the pad and carpet they can then be brken ff at the face f the sheathing. (A special tl is required.) If yu can reach the jists frm belw, drill a hle thrugh the tp flange f the jist and partially int the sheathing, then install a screw t pull them tight. www.nascr.ca 4
Sheathing issues (cnt d.) When the wrng sheathing is used, it may result in excessive deflectin, causing mvement and therefre squeaks thrughut the flr. Use a sub flr that is thicker than that required by the Building Cde. Add anther layer f decking ver the existing sub flr. Installing blcking between the flanges f the jists alng the sheathing seams (if the flr is accessible frm belw) may als help. Use adhesive t bnd all cntact surfaces, and nail the blcking carefully t prevent new squeaks. When sheathing is installed imprperly, squeaks at the jist r T&G jint can result. Leave a ⅛" vid at all edges and end jints. Use adhesive n all T&G jints. Sheathing shuld be adhered t the jists with slvent-based adhesive that cnfrms t APA-The Engineered Wd Assciatin perfrmance specificatin AFG-01. Apply enugh adhesive fr nly 1 r 2 panels at a time s that the adhesive desn t set prir t installatin. Apply tw lines f adhesive where the panel ends meet. Extend the adhesive all the way acrss the panel and nail befre the adhesive sets. Fr squeaks at the jist, re-attach the sheathing t the jists with the apprpriate nail r screw. Fr squeaks at T&G jints, install a 2x4 blck directly under the jint and screw thrugh. Lcate the screws n bth sides f the T&G jint and apply adhesive between the sheathing and the blck. Alternatively, a saw kerf cut at the jint may stp the squeak. www.nascr.ca 5
Underlay issues When underlay is nt installed prperly, squeaks r ther nises can ccur. Often, the nises are intermittent and may cincide with changes in temperature and Relative Humidity. Fllw the manufacturer s recmmendatins fr installatin f the underlay. Ensure dust and debris is remved frm the sub flr befre placing the underlay. Offset the underlay jints frm the sub flr jints. Prperly attach the sub flr t the underlay by nailing, stapling, r gluing and nailing. Partitin wall issues Fr an islated squeak where access frm belw is pssible, drill a hle thrugh the sub flr and partially int the underlay. Install a screw that is lng enugh t reach at least half way thrugh the underlay. Fr squeaks thrughut the flr, the carpet shuld be pulled back and the underlay reattached. When the partitin flr is nailed nly t the flr sheathing and a lad is applied, the sheathing deflects and rubs n the shank f the nail, resulting in a squeak. When studs are cut t shrt, it can als result in nails squeaking at the bttm f the wall, between the plate and studs. Nail interir partitin walls t the jists. Where the partitin runs parallel t the jists and extends ver mre than half f the jist span, add a jist under the partitin. If this is nt pssible, run a bead f cnstructin adhesive under the wall and either crss-nail, nail thrugh and clinch tight r screw frm belw. Anther ptin is t bridge between the jists and attach wall at blcking lcatins. If accessible frm belw, install screws thrugh the flr sheathing and int the bttm plate f the wall. Otherwise, remve the basebard alng the partitin and drill a hle (larger than the screw shank) thrugh the bttm plate f the partitin at a 45 degree angle. Use a screw t pull the flr sheathing up t the partitin. Nn Ladbearing Wall Sheathing Blcking www.nascr.ca 6
General recmmendatins fr the preventin and cure f squeaks High quality cnstructin adhesive is imprtant. Use slvent-based adhesive that will bnd wd and metal. All fasteners attaching the sheathing t the jists shuld be driven vertically, nt at an angle. The best fastener t use fr nailing flr deck sheathing t the Nascr jist is a defrmed shank nail. Screws are als gd, but nly if the tp ¾" f the screw under the head has n threads. D nt use smth, cement r vinyl cated nails. Always install hardwd flring perpendicular t the jists. Fllw the manufacturer's recmmendatins. T minimize vibratin in flrs withut direct applied ceilings, attach 1x4 strapping (perpendicular t the jists) t the underside f the bttm flange f each jist with tw 8d (2½") nails. Run cntinuus strapping at 8' ncenter and tie it ff at the end walls. When the finished flr and ceiling have already been installed, it can be difficult t access t a flr squeak. A recmmended methd is: Pull back the carpet and pad. Use a stud finder t lcate the jists, r prbe thrugh the sheathing with a pattern f nailing. Cut a 4" hle thrugh the sheathing between the jists. Fix the prblem (see recmmendatins fr specific prblems abve). T repair the hle, put 2x4 blcks with adhesive already applied thrugh the hle, then pull them up against the bttm f the sheathing and screw them in place. Glue and screw the 4 cut-ut sheathing piece back in place n the 2x4s. Fr mre infrmatin n Nascr prducts and their prper installatin, cntact Nascr at 1.800.668.2365. www.nascr.ca 7