Weak WiFi signal on the second floor

[KWLee]

My cable modem is installed on the ground floor. But the WiFi signal is comparative weak on the second floor. May I ask any altrenatives for improvement?

[Mamfa010]

Same! Ive literally just had sky put into my new house, the box is downstairs, open reach have drilled a hole and put the box and router behind my corner sofa, he said it wont affect the signal, there is no where else to fit my sofa but there was another open wall he could of fitted the box to, every time im upstairs my phone doesnt work on wifi at all! Having to use my mobile data, not impressed at all, even downstairs the signal is poor too. 

[TimmyBGood]

@KWLee @Mamfa010 

Sky loans wireless booster hardware free under the terms of the 'WiFi Guarantee' element of 'Broadband Boost' and the 'Enhanced Wall to Wall WiFi Guarantee' part of the 'WiFi Max' subscription supplement: they don't otherwise provide or sell them except to resolve issues with Sky Q. Inevitably some have leaked onto a certain auction site, but Sky won't offer support with using these. 

Confusingly the 'Wall to Wall WiFi Guarantee' doesn't actually provide booster hardware, and is essentially a sales lead generator for the supplements mentioned above.