Due to our location (limited LOS to Waltham Tx, same for Sutton Coldfield Tx) I fought a losing battle from 2000-2011 with TV amplifiers & DVB-T.
The problem with DVB-T is that its simply not as resilient as the old analogue system - mainly because the Tx power levels are usually < 20% of the analogue Tx levels. It doesn't help that many of the multiplexes have what I consider to be borderline overloading in terms of the number of channels & channel encoding.
On top of the problems with amplifying noise & dreadful signal discrimination I found that various receiver front-ends would be overloaded while others were fine - this from the same amp output. So I bit the bullet & got an amp with variable gain on each output & put that in the loft. That was OK until one of the frequent changes to multiplexes happened (we've had 5 changes of frequency & probably a dozen changes to multiplex encoding) which would require manual adjustment of outputs again.
I even installed a couple of these (older models) :
http://www.silicondust.com/products/hdhomerun/hdhomerun-connect-au/ as it was getting to the stage that streaming over the network was easier than balancing out each receiver.
Then "HD" came along using 256QAM which would require new DVB-T receivers.....
Anyway I got sick of this & decided to get Sky to install a sat dish with 4 LNBs (outputs). Hooked a "Freesat" (DVB-S) box up to the spares & it works much much better than "Freeview" (DVB-T).
tl;dr if you have garbage reception then DVB-T is a waste of time & money - get a dish installed & switch to DVB-S.