"Waka Kotahi apologises for the delay in switching traffic over to the detour and for any confusion caused.
"Weather plays a big part in how our work is programmed and at this time of year, work can often be disrupted due to cooler temperatures and rain."
Contractors were focussing on sealing the road early Friday morning and aimed to have the detour in place around midday, she said.
The detour
A short section of State Highway 36 will be closed, with people travelling from Rotorua to Ngongotahā, Hamurana and Tauranga detoured via State Highway 5 and Western Rd.
The detour does not affect southbound traffic heading into Rotorua.
This work will be clearly signposted to help road users know where to go.
To help with traffic flow, the new SH5 and SH36 roundabout free flow (slip) lane will be opened and two temporary roundabouts installed - one at the SH5 and Western Rd turnoff and one in Ngongotahā Village at the SH36 and Western Rd intersection.
Manual traffic control may also be in place at times.
While the detour is in place there will be extra traffic along Western Rd. The detour will be monitored to ensure traffic is flowing and adjusted if necessary.
The changes are expected to be in place for up to six weeks.
Motorists are asked to take extra care while the detour is in place, especially at the Ngongotahā Village end.