Calculate the amount of force exerted by the atmosphere on the roof of your house (area = 95 m2) if the pressure is 101,000 Pa.?

Force, F
= P A
= (101,000 N/m²) × (95 m²)
= 9,600,000 N (to 2 sig. fig.)

outer force OF =  95*1.01000*10^5 = 9.6*10^6 N
inner force IF = -OF  = -9.6*10^6 N
net force NF = OF+IF = 9.6*10^6-9.6*10^6 = 0 

zero, the forces on the top of the roof pushing down balance those under the roof pushing up. There is a small difference, but that depends on the thickness of the roof and it pushes up by a tiny amount.