The chapel area will be closed from Monday, January 23, until June.
Cremations will still take place but families will have to hold services in alternative locations.
Falkirk Council says the £3.2 million refurbishment is being carried out in two phases to bring it up to current standards and improve the comfort for grieving family and friends.
The announcement comes as the local authority admits that a ‘double booking’ at the crematorium last Friday was its error.
The refurbishment work, which includes increasing the size of the chapel to for additional mourners, had been due to begin last August but was put on hold while further consultation with stakeholders took place.
There will be a phased replacement of the three cremators when the chapel will be available but there will be no weekend cremations.
Councillor Craig Martin, spokesperson for the environment, said: “This is a significant investment for the crematorium and its first major upgrade since it opened in 1962.
“Unfortunately building and improvement works on this scale will cause disruption to normal services in the crematorium chapel.
“We are working closely with funeral directors and faith groups and will continue to keep them up to date with information on the works, timescales and any changes to current arrangements.”
With funeral services needing to take place elsewhere, charges for cremations are being reduced to allow families “flexibility” to arrange alternative locations without incurring additional expenses.
The upgrade work follows consultation on bereavement services which has already seen services extended to 45 minutes and additional car parking.
During the upgrade, the Book of Remembrance will be moved to an alternative location near the crematorium for those wishing to pay their respects.
The public will still have access to the cemetery, Garden of Remembrance and the SANDS memorial.
Falkirk Council has apologised for last Friday’s mix-up when two groups of mourners turned up at the same time for services.
One family had to wait an additional 45 minutes before the service for their relative could begin.
Rhona Geisler, director of development services, said: “We are extremely sorry for any distress this may have caused mourners attending both funerals.
“We deal with thousands of interments and cremations every year which are handled in a professional and dignified manner by all staff involved and will do everything possible to make sure this regrettable incident does not happen again.”
For more information on the work, visit www.falkirk.gov.uk/crematorium, or pick up a leaflet in council offices and public buildings.