Animate height change of UITableView section header

I have seen almost all the posts here on this topic, but I can't get the result I want. I am trying to increase the size of a sectionHeader while a transfer is happening. Using this code, I get the desired result, with one exception, that my footers are also animated down from the top again.

UIView.animateWithDuration(0.3) { () -> Void in
            self.m_transferInProgress = true
            self.tableView.beginUpdates()
            self.tableView.endUpdates()
        }

// The m_transferInProgress is used in heightForHeaderInSection
        override func tableView(tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
            if section == 0 && m_transferInProgress {
                return m_transferSectionHeaderHeight
            }
            return 90
        }

How can I get only the sectionHeaders to animate when using beginUpdates()?