Design Rothoblaas Brackets to Eurocode 5

Rothoblaas (Rotho Blaas Srl, Cortaccia, Italy) has supplied fastening and connection systems for timber construction since 1991. Its face-fixed steel brackets and hold-downs are recognised under three European Technical Assessments issued against EAD 130186-00-0603 for three-dimensional nailing plates: ETA-11/0496 for the TITAN angle brackets, ETA-22/0089 for the NINO angle brackets and WKR hold-downs, and ETA-23/0813 for the WHT hold-downs. SPEC Toolbox designs them to Eurocode 5 on the characteristic capacities of those assessments.

Plates are carbon steel (DX51D, S250GD, S350GD, S235, S275 or S355) coated Z275 or Fe/Zn12c, 1.5 to 5.0 mm thick, one-piece and non-welded apart from the welded WHT hold-downs. They fix to timber with ringed-shank connector nails or self-tapping screws, and to concrete or steel with bolts or metal anchors.

Hold-downs

• WHT15, WHT20, WHT30, WHT40 and WHT55, 250 to 600 mm high, with WHT washers.
• WKR9530, WKR13535, WKR21535, WKR28535 and WKR53035, 95 to 530 mm high.
• TCN200, TCN240 and TCS240 with the TITAN washers TCW200 and TCW240.

Angle brackets and shear angles

• TITAN N: TCN200 and TCN240 to concrete, TTN240 to timber, TTN240 also with XYLOFON.
• TITAN S: TCS240 to concrete, TTS240 to timber, TTS240 also with XYLOFON.
• TITAN F: TCF200 and TTF200, 71 mm deep, TTF200 also with XYLOFON.
• TITAN V: TTV240, a 4 mm angle for uplift at wall ends and shear along the wall, also with XYLOFON.
• NINO: NINO100100, NINO15080, NINO15080S and NINO100200, with NINO washers.

Shear plates

• TITAN PLATE T: TTP200, TTP300 and TTP1200, the last for continuous floor connections.
• TITAN PLATE C: TCP200 and TCP300, for concrete or masonry to CLT.

Tension straps

• WHT PLATE T: WHTPT300, WHTPT530, WHTPT600, WHTPT720 and WHTPT820, 300 to 826 mm long.
• WHT PLATE C: WHTPLATE440 and WHTPLATE540, for walls at the concrete edge.

The TITAN PLATE shear plates and WHT PLATE tension straps are supplied in addition to the assessed families.

At a glance, the Rothoblaas brackets support:

• Timber-to-timber, timber-to-concrete and timber-to-steel connections.
• Solid timber, glulam, LVL, PSL, LSL, CLT and plywood at characteristic densities of 290 to 420 kg/m3, and 290 to 460 kg/m3 for the WHT hold-downs, with LVL to 500 kg/m3 fastened in the wide face.
• Tension and uplift (F1) across the range, with shear (F2/F3) and lateral (F4/F5) directions for the TITAN and NINO brackets and the WKR hold-downs, under a quadratic combined-force interaction.
• Fixing with connector nails, screws, bolts or metal anchors, each set with its own tabulated capacity.
• A soundproofing or wood-based interlayer up to 26 mm between the plate and the timber.
• Timber of strength class C14 or better, restrained against rotation and free from wane.
• Service classes 1 and 2, and class 3 with corrosion protection to Eurocode 5 or equivalent stainless steel.

• Acoustic interlayers assessed in the connection. XYLOFON, Aladin Stripe Soft and Extrasoft interlayers carry their own capacities on TTN240, TTS240, TTF200, TTV240 and NINO, so a decoupled joint uses tabulated values.
• Assessed gap and stand-off installations. Both families have separate values for a gap under the horizontal flange: WHT k_t moves from 1.09 to 1.0, gapped WKR uplift caps at 19 kN, and WKR tables reach a 360 mm stand-off.
• Several fastening options per bracket. One bracket is assessed with LBA nails, with LBS, LBSH, HBS, HBSP, HBSPL or TBS screws, and, on TITAN V and NINO, with VGS screws set at an angle.
• Capacities tabulated per fastener pattern. Values cover numbered full and partial nailing patterns, up to twelve for NINO and wide or narrow on WHT, so a reduced pattern uses assessed values, not pro rata.
• Connection stiffness. Slip moduli are given per bracket, fastener and load direction, and in ETA-22/0089 and ETA-23/0813 as a fraction of the governing capacity.

The Rothoblaas brackets are available in the bracket module and CLT Shear Wall calculator, worked to Eurocode 5:

• hold-down (tension and uplift anchorage);
• angle bracket and shear angle (shear and combined loading);
• shear plate;
• tension strap.

Capacities are selected for the assigned strength class and density, the fastener set and the load direction, with end, edge and spacing rules from the assessment.

Design follows Eurocode 5 (EN 1995-1-1). The assessments give characteristic capacities in the F1 (tension and uplift), F2/F3 (shear) and F4/F5 (lateral) directions, with connection slip moduli. The design capacity is the lesser of the timber-connection failure (fastener embedment or withdrawal, with k_mod and the connection partial factor) and the steel-plate failure (with the steel partial factor), plus a concrete branch for the WHT hold-downs. Capacities are stated at 350 kg/m3 and adjusted by k_dens, and lateral fastener capacities assume a thick steel plate except with screws above 5.0 mm. Splitting under the lifting force, block shear, end bearing and the design of bolts or anchors are verified per Eurocode 5.