Someone on here could probably give you a good rundown of what he may have experienced as a Royal Engineer, but you seem to be after specifics.

It may be best to contact the army and ask for information that way. I'm sure they have some kind of records available for you to dig through, especially with all of the centennial stuff going on for the war. Look for any regimental histories too.

You should also contact the Cemetery. I bet they'll at least have info on where he died, which may be helpful for approaching army records.

Also, thanks for doing this. Records on this sort of thing usually only get harder to find over time and it's good that you're working on it.

If you are trying to find out specifically how he died you may have some success if you can access the Red Cross Society Wounded and Missing Enquiry files. I do not know about accessing them for British soldiers but I do know that many of them for Australian soldiers killed in France during WW1 have been digitised and are available online through the Australian War Memorial. I would expect some similar facility for British soldiers. Include the Service Number in any search to avoid name ambiguities.

Typically, the Australian Red Cross Society sought statements from fellow soldiers in the unit and if possible, immediate superiors about what had happened. A typical file would include several short (perhaps a paragraph or two) statements from different persons describing the event and surrounding circumstances, and perhaps where he was buried. They were typically taken weeks or months later so might not agree in all details.

I found this website. I've put in your grandfather's info, but if it doesn't work, you can start again at the homepage. It does cost a subscription, but you may be able to find something.

EDIT: I've used my ancestry.com membership to search for your grandfather, but I'm only getting the info you already have. I'm also being told by other sources that he has/had no bio.