ScanSnap Home is not able to automatically merge together the scanned left and right page images when scanning a document separated by a page fold.
Use an optional Carrier Sheet to scan a document separated by a page fold and automatically merge together the left and right page images of the document.
About the Carrier Sheet:
ScanSnap Help - Part Numbers of (Carrier) Sheets
(Select the model name of the ScanSnap at the top of the page)
If you already have two scanned pages you want to manually merge to create a double-page spread image, please refer to the following.
ScanSnap Help - Creating a Double-Page Spread Image by Merging Two Pages
(Select the model name of the ScanSnap at the top of the page)