HTT

Hold Down

Ideal for existing or new construction, HTT Tension ties provide a high strength timber to concrete, or timber to masonry, tension connection

The long vertical leg makes it possible to add the required number of fasteners (CNA Nails and CSA Screws) in a vertical post and still comply to relevant standards with regards to fastener spacing requirements.

The unique design of the HTT - a multi ply seat formed from a single piece of steel - gives the tension tie extra strength at the concrete / masonry anchorage point

CE Marking
ETA
Service class 2
Indoor
Electrogalvanized steel Z275

Product Details

Images

Features

Material

Z275 Pre-galvanised mild steel.

Benefits

  • Enables a connection to concrete structure.

Application

Connections

Timber Members

When to Use

  • Timber structures which exerted to high uplift forces can be connected to concrete structures with the HTT Hold Down.
  • Tension force connection between timber floor joists and masonry walls

Technical Data

Dimensions

Product Dimensions

References Product Dimensions [mm] Flange A Flange B
A B C D E t Ø4,7 Ø5 Ø21 Ø17,5 Ø18 ∅25
HTT4 314 60 64 11.4 35 2.8 18 - - 1 - -
HTT5 403 56 64 11.4 35 2.8 26 - - 1 - -
HTT22 559 62 64 11.4 33 2.8 32 - - 1 - -

Capacities

References Number of Fasteners Characteristic capacities - Timber C24 to concrete [kN]
Joist Flange B R1.k (without US50/50/8 washer) R1,k (with US50/50/8 washer)
Qty Type Qty Type CNA4,0x35 CNA4,0x40 CNA4,0x50 CNA4,0x60 CSA5,0x35 CSA5,0x40 CSA5,0x50 CSA5,0x80 CNA4,0x35 CNA4,0x40 CNA4,0x50 CNA4,0x60
HTT4 n CNA 1 M16 min [(n-3.5)*1.66; 15.4; 43/kmod] min [(n-3.5)*1.83; 18.6; 43/kmod] min [(n-3.5)*2.22; 24.7; 43/kmod] min [(n-3.5)*2.36; 31; 43/kmod] - - - - min [(n-3.5)*1.66; 19.7] min [(n-3.5)*1.83; 23.9] min [(n-3.5)*2.22; 31.7] min [(n-3.5)*2.36; 39.7]
HTT5 n CNA 1 M16 min [(n-3.5)*1.66; 15.4; 43/kmod] min [(n-3.5)*1.83; 18.6; 43/kmod] min [(n-3.5)*2.22; 24.7; 43/kmod] min [(n-3.5)*2.36; 31; 43/kmod] - - - - min [(n-3.5)*1.66; 19.7] min [(n-3.5)*1.83; 23.9] min [(n-3.5)*2.22; 31.7] min [(n-3.5)*2.36; 39.7]
HTT22 n CNA 1 M16 min [(n-3.5)*1.66; 15.4; 43/kmod] min [(n-3.5)*1.83; 18.6; 43/kmod] min [(n-3.5)*2.22; 24.7; 43/kmod] min [(n-3.5)*2.36; 31; 43/kmod] - - - - min [(n-3.5)*1.66; 19.7] min [(n-3.5)*1.83; 23.9] min [(n-3.5)*2.22; 31.7] min [(n-3.5)*2.36; 39.7]

Quantity of fasteners (n) may be choosen by the user. Capacity is then calculated with this number n.
(1) n is equal to 10 a maximum.
(2) 4 CSA5.0x80 must always be installed on the bottom extremity of the oblong holes to reach the capacities given in the table. For other fastener in these 4 holes, the capacaity shall be calculated according to ETA.

Product capacities - simplified values

References Product capacities - Timber to Concrete
Number of Fasteners Characteristic capacities - Timber C24 to concrete [kN]
Flange A Flange B R1.k (without US50/50/8 washer) R1.k (With US50/50/8 washer)
Qty Type Qty Type CNA4.0x35 CNA4.0x40 CNA4.0x50 CNA4.0x60 CSA5.0x35 CSA5.0x40 CSA5.0x50 CSA5.0x80 CNA4.0x35 CNA4.0x40 CNA4.0x50 CNA4.0x60
HTT4 18 CNA 1 M16 15.4 18.6 24.7 31 - - - - 19.7 23.9 31.7 34.2
HTT5 18 CNA 1 M16 15.4 18.6 24.7 31 - - - - 19.7 23.9 31.7 34.2
HTT22 32 CNA 1 M16 15.4 18.6 24.7 31 - - - - 19.7 23.9 31.7 39.7

Simplified numerical characteristic capacities values are based on load duration and service class assumption (Instantaneous, Service class 2, kmod = 1.1). For other load duration, service class and fasteners, please refer to ETA-07/0285.

For HTT31, 4 CSA5.0x50 must always be installed on the bottom extremity of the oblong holes to reach the capacities given in the table. For other fasteners in these holes, the calculation shall be calculated according to ETA.

Product capacities with Zyklop, simplified

References Product capacities with ZYKT [kN]
Fastener Characteristic capacities - Timber C24 to concrete [kN]
Flange A Flange B R1.k
Qty Type Qty Type Qty Type
HTT4 - - - - - - -
HTT5 - - - - - - -
HTT22 - - - - - - -

The capacities for the ZYKT69 are determine for an embendingth length of the screws of the ZYKT of 280 mm. Details of the Zyklop are givne in ETA-07/0317.

The essential CNA / CSA have to be place in the oblong holes (lower side), and for the HTT22E also in the 2 lowermost holes Ø5 mm.

Simplified numerical characteristic capacities values are based on load duration and service class assumption (Instantaneous, Service class 2, kmod = 1.1). For other load duration, please refer to ETA-07/0285.

 

Installation

Installation

Fixing

Fastening into Timber Stud:

  • 4mm CNA Nails
  • 5mm CSA Screws

 

Fastening to the concrete:

  • Mechanical anchors: M16 WA Anchor or BOAX-II
  • Chemical anchors: injection mortar SET-XP or AT-HP + M16 threaded rod LMAS

 

Installation

  • The connector is mounted with a suitable M16 bolt to the concrete or masonry wall,  and the vertical leg is fastened with 4mm CNA Nails, or 5.0mm CSA Screws,  to the timber.

Certification

European Technical Assessment (ETA)